Bayern Munich is already through to the second round of theChampions League, and Manchester City is hoping that will help their own chances of advancing.
City needs to beat the Bundesliga champions at home on Tuesday to boost its hopes of making it out of the group.
A draw would still be enough for the English champions to remain in the competition if CSKA Moscow and Roma also draw at the same time.
Here are some things to know about Tuesday's games:
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CITY HANGING IN
Man City will take heart from its 3-2 win over Bayern last season, when it ended the German side's Champions League record of 10 straight victories. Again, Bayern was already assured of topping the group and had nothing but pride to play for.
City, which came from behind to edge Swansea 2-1 on Saturday, is still looking for its first Champions League win of the campaign and looks like it will exit the competition at the group stage for the third time in four attempts.
"We're really lucky in the Champions League because with two points and two games left we can still qualify if we win our two games," City midfielder Samir Nasri said. "We need a big reaction. We need a huge performance, because a team like us can't go out in the first round of the Champions League. So we have to win this game."
Roma and CSKA are both two points ahead of City, which visits Roma for its final group game.
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LJAJIC IN FORM
With Roma forward Adem Ljajic coming into form, coach Rudi Garcia could consider giving the Serbia international his first Champions League start in Moscow.
Ljajic has made two substitute appearances in Europe's elite club competition but scored in Roma's past two Serie A matches.
"He's on another level," said teammate Radja Nainggolan, who scored the other goal in Saturday's 2-1 victory at Atalanta. "He just needs consistency and he's working really hard for that.
"He's had a lot of criticism and he's always answered on the pitch. He made the difference."
Ljajic was punched by his coach at Fiorentina, Delio Rossi, after protesting a substitution in May 2012. Rossi was fired, and the next season, Ljajic scored a career-high 11 goals for Fiorentina but again had problems with his coach, Sinisa Mihajlovic.
Since transferring to Roma before last season, Ljajic appears to have settled down.
Roma is level on points with CSKA, which it beat 5-1 in its opening match.
Group F
Lionel Messi chasing new record at APOEL
After becoming the Spanish league's all-time leading scorer over the weekend, Lionel Messi is chasing another milestone in the Champions League.
The Argentina forward is even with Raul Gonzalez's all-time record of 71 ChampionsLeague goals, and he could better that on Tuesday when Barcelona travels to Cypriot club APOEL on Tuesday in Group F.
"He doesn't stop breaking records," Barcelona defender Jordi Alba said. "It's a privilege to have Messi as a teammate."
Barcelona has already qualified for the second round while APOEL is last in the group and looking for its first win.
Also, unbeaten leader Paris Saint-Germain hosts Ajax, with the Dutch side now aiming for a third-place finish and a place in the Europa League.
Here are some things to know ahead of Tuesday's matches:
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SUAREZ'S FIRST?
Barcelona overlooked Luis Suarez's checkered past and his most recent biting ban when it signed him for his scoring prowess. But the Premier League's top scorer last season has so far only excelled at helping others to score and is still looking for his first goal for Barcelona.
Suarez has assisted on four goals in five appearances, and the Uruguay forward will surely be eager to finally get his debut goal against APOEL.
That is unless coach Luis Enrique decides to rest him and some other first-choice starters with Barcelona facing four matches in a 16-day span.
Barcelona has a tough visit to Valencia in the Spanish league looming on Sunday. It then starts its Copa del Rey campaign next week before hosting Espanyol in a city derby. And after that, PSG arrives on Dec. 10 for a match that could decide which team claims top spot in the group and more favorable seeding going into the second round.
"We need to go forward game by game," Barcelona midfielder Sergio Busquets said. "We play in the Champions League first and have to take it step by step. We must make a big effort to win them all."
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INJURY-HIT PSG
Although only the most dedicated fans would consider betting on Ajax's chances of beating PSG, the French champions' injury worries might give a slight chance to the Dutch side.
Midfielders Yohan Cabaye and Thiago Motta were replaced during PSG's 3-2 win over Metz in the French league because of calf problems, while David Luiz, Lucas and Marco Verratti were not fit enough to play.
"This is what happens to clubs who have a lot of international players. You need to be able to deal with it," PSG coach Laurent Blanc said.
Zlatan Ibrahimovic started for the first time in two months against Metz following a heel injury, but the former Ajax striker - who has not scored for PSG since a hat trick at the end of August - said he needs some more time to play at his best again.
Ajax, which has scored four goals in four of its last five games, will be without the suspended Joel Veltman, who has been replaced by Stefano Denswil in the squad.
Group G
Schalke coach Di Matteo meets Chelsea again
GELSENKIRCHEN, Germany (AP) - Roberto di Matteo will face his old club when Schalke hosts Chelsea in the Champions League on Tuesday.
Di Matteo was in charge when Chelsea stunned Bayern Munich to win the 2012Champions League title. But he was fired in November of that year.
Now, Di Matteo is back at the helm of Schalke. He was still not in charge when Schalke earned a 1-1 draw at Chelsea at the start of Group G and only became coach after the firing of Jens Keller.
Sporting Lisbon hosts last-place Maribor in the other group match.
Here are some things to know about Tuesday's matches:
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HOW THEY ADVANCE
Chelsea, with eight points, will be through with a win or any draw in which it scores two goals or more.
Schalke, which has five points, will go top with a win but cannot go through or be eliminated for now.
Sporting has four points and will be out if it loses. Maribor will be out if loses or it draws and Schalke wins. Maribor has three points and will finish fourth if it loses and Schalke wins.
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SEE YOU AGAIN
Roberto di Matteo says playing against the club he guided to European glory will not be anything extraordinary.
"I will concentrate on my job and try to win with Schalke against Chelsea," Di Matteo said.
Di Matteo was promoted from an assistant to head coach before winning theChampions League on penalties against Bayern Munich. But that was not enough to save his job before the year was over.
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DI MATTEO AHEAD OF MOURINHO
Jose Mourinho has a far more illustrious coaching career than Roberto di Matteo, but the Portuguese still has to win the Champions League as coach with Chelsea.
Mourinho has won the title with FC Porto and Inter Milan but not with Chelsea, whose only title in the top competition was under Di Matteo.
Mourinho is seeking to become the first coach to win the Champions League with three different clubs.
Group H
Luiz Adriano eyes Champions League record
While Lionel Messi tries to break the Champions League's all-time scoring mark on Tuesday, another record could fall when Shakhtar Donetsk forward Luiz Adriano faces Athletic Bilbao.
The Brazilian is having a breakout European campaign and has Shakhtar on the cusp of qualifying for the second round for the third time in five seasons despite the turmoil in Ukraine.
A win by Shakhtar will put the Ukrainian champions through from Group H, along with the already qualified FC Porto, which visits BATE in Belarus.
Here are some things to know about Tuesday's matches:
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RECORD TO FALL
Luiz Adriano has already matched the feats previously reached only by Messi and Cristiano Ronaldo.
He has scored nine goals through the first four matches, equaling the record set for group goals by Ronaldo.
Luiz Adriano also matched Messi's single-game milestone by scoring five times against BATE last month.
The 27-year-old Brazilian will face a Bilbao defense that held his team to a 0-0 draw in their first meeting this season.
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OVERSTAYED WELCOME?
Shakhtar continues to play its home matches in the western city of Lviv because of ongoing political and military strife in Ukraine, and the strain is beginning to show.
Shakhtar left its Donbass Arena located in the city of Donetsk, now controlled by pro-Russian rebels, last spring. The stadium has since been damaged by shelling.
But its relations with host club Karpaty Lviv have deteriorated as well.
Over the weekend, the two clubs played each other and Karpaty demanded both squads wear warm-up shirts with a message of support for the Ukrainian army. Shakhtar, being from the east, branded this "a pure provocation" that would alienate its fans, and refused. At Shakhtar's last Champions League game, a banner was briefly displayed by locals demanding the club leave Lviv.
But Shakhtar midfielder Dentinho said Lviv is a welcoming host.
"In this match the support will be on our side," Dentinho said. "We, of course, are missing our Donbass Arena. But now our home stadium is in Lviv, and the people are rooting for us here."