Avengers: Infinity War - 10 MCU Heroes Strong Enough To Face Thanos
10. Captain America
Captain America's shield has proven capable of withstanding a powerful blow from Thor's hammer, Mjolnir, so assuming Steve Rogers is outfitted with a similar vibranium accessory (y'know, "get this man a shield"), he should be able to stand up to Thanos for a while.
The power in that Mjolnir strike has to be on the same level - or a higher level - than a punch from Thanos, meaning that as long as Steve can use his shield wisely and keep front toward enemy, he can block punches, kicks, and jabs, returning a few of his own inbetween.
Whether Steve's punches will have any effect on Thanos, we don't know, but he's a skilled, experienced fighter, so even if his attacks are too weak to register, he'll be able to keep the Mad Titan occupied while a stronger hero dishes out the pain.
But if he's just fighting and defending with his own two hands - i.e. he lacks a shield, or something else as strong as vibranium - he won't last anywhere near as long.
Yes, he's a lot smaller than Thanos so he should be able to dodge and avoid some attacks, but one punch from this opponent could break Steve's bones. Plus, since Steve can't fly like a lot of other heroes, his manoeuvres are limited, and he doesn't have many escape options if he's struggling.