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Captain America

While everybody believes that Captain America will die at the end of Civil War, we remain circumspect about this possibility. After all, Chris Evans still has one more movie on his contract. Furthermore, killing him only to have him resurrected won't cut it "“ it has happened before and we believe the fans won't take it so lightly once again. So yes, Steve Rogers will be in at least one of the Infinity War movies.
Afterwards, it all depends on how he negotiates his contract.
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The Winter Soldier

Back when Sebastian Stan was cast as Bucky Barnes, he said he has a 9 movie deal with Marvel. Civil War will be his third "“ so it is a given (we say) for him to survive and make it into the Infinity War. Furthermore, if Steve Rogers will indeed die for one movie, he might become Captain America himself"¦
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Falcon

At the end of Age of Ultron, the Falcon was revealed to be one of the newest members of the Avengers. Seeing that the roster will keep changing, we are wondering whether or not he'll have a bigger role to play in the following movies.
In any way, even if he is going to meet his end, it will be in the fight against Thanos and his minions. Will it be in the first or the second Infinity War? We don't know, but we expect for Falcon to be there.