MADRID (AP) Barcelona is through, and Ajax needs a win in Group H of the Champions League.
With two games remaining, Barcelona leads the Group H with 10 points. AC Milan is second with five points, followed by Ajax with four and Celtic with three. AC Milan visits Celtic in the other group match.
Here are 5 things to know ahead of Tuesday's matches:
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MILAN CRISIS
Seven-time champion AC Milan remains in crisis mode ahead of its visit to Celtic.
The Rossoneri are on a five-match winless streak in Serie A and haven't won in Europe since beating Celtic 2-0 in the opening round of group matches in September.
Milan's poor form has mirrored that of striker Mario Balotelli, who has gone six matches in all competitions without a goal and failed to convert a penalty kick in Saturday's 1-1 draw at home with 10-man Genoa.
Balotelli raised eyebrows when he tweeted at 5 a.m. Sunday, "This is the end. :-)"
With Milan coach Massimiliano Allegri barely clinging to his job, one of the few bright spots has been the return of Brazil playmaker Kaka.
After an injury-plagued four-year spell at Real Madrid, Kaka is back to a reliable attack weapon and scored the opener against Genoa.
For the trip to Glasgow, Milan is without several players, with center back Philippe Mexes and midfielder Sulley Muntari the latest to join the injured list.
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INJURY BUG
Barcelona will be able to count on midfielder Xavi Hernandez for its visit to the Amsterdam Arena, but fullback Adriano has joined the Spanish champion's growing injury list.
Barcelona is already without forward Lionel Messi, goalkeeper Victor Valdes, defender Jordi Alba and defender Dani Alves, all because of injury. With Adriano's absence on Tuesday, Marc Montaya is the only remaining natural back in defense.
Barcelona coach Gerardo Martino has had to call in four youth team players to complete the 19-man squad. But the Argentine coach is confident his club will adapt as it did in Saturday's 5-0 rout of Granada.
"This team knows how to play in a different way when it needs to," Martino said.
Barcelona, which has yet to lose in 20 matches this season, will win the group even if it loses as long as Celtic beats Milan.
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STRIKERS OUT
Four-time European champion Ajax desperately needs a win against Barcelona to keep alive its hopes of qualifying for the knockout stage, but the question for coach Frank de Boer is: Where will goals come from?
The defending Dutch champions have an injury crisis in their front line with recent internationals costing Ajax the services of captain Siem de Jong and Iceland striker Kolbeinn Sigthorsson. De Jong picked up a hamstring injury playing for the Netherlands against Colombia and Sigthorsson damaged an ankle in the first leg of Iceland's World Cup playoff against Croatia.
Add to that Bojan Krkic's long-term hamstring injury and Ajax will be forced to field a makeshift front three at the Amsterdam Arena.
Two likely candidates to start in the attack, Danny Hoesen and Viktor Fischer, scored in Saturday's 3-0 victory over Heracles Almelo.
"It's good for their confidence that they scored," De Boer said. "They did their absolute best, but I know they can do even better."
Ajax will move into second if it wins and Milan does not.
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FLYING HIGH
Celtic is on a high after a pair of stoppage-time goals secured a 3-1 victory over Aberdeen on Saturday for the Scottish leaders.
After scoring his first Celtic goal on Saturday, winger Derk Boerrigter is hoping to inflict damage on Milan.
"I am not entirely over my ankle injury but we are working hard to get there," said Boerrigter, who joined from Ajax in the offseason. "It has been a long time. Before I came here I had the injury and I got a lot of kicks on it here. I got time off to recover and that helped and I am feeling better now."
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FILLING IN FOR LEO
Lionel Messi's football hasn't been doing the talking of late, but his teammates in attack have been filling in adeptly for the Barcelona forward.
Now they will have to respond in Europe.
Cesc Fabregas, Alexis Sanchez, Neymar and Pedro Rodriguez have combined for 26 goals this season, but only Fabregas has scored in the Champions League this season. Messi netted six times in the continental competition before a hamstring injury sidelined him.
Barcelona coach Gerardo Martino's lineup could see either Fabregas or Neymar lead the attack despite neither normally playing in the traditional striker's spot. Sanchez is suspended for the match.
"Neymar can play the 'false 9' well," Martino said. "I don't think it's extra pressure for Neymar. He's already assumed the role before when Leo was absent against Atletico and Almeria."
Messi, who scored two goals in Barcelona's 3-1 victory over Milan in the last round, has scored 14 goals for four-time European champion Barcelona this season.
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Follow Paul Logothetis on Twitter @PaulLogoAP
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