[ Steve doesn't know him well enough to understand that the words, I'm the last person you need to worry about do little to reassure the Doctor, and in fact, have the opposite effect. He knows the type. Or, he thinks he does. He thinks a lot of things, not all of them correct, and he'll be more than willing to adjust his assumptions as time goes on and they know each other better.

But "resilient" and "super fast metabolism" are all well and good, of course. Certainly, he wouldn't deny the other man is physically strong, able to withstand far more than the average human, helpful to have in a fight, more than capable of protecting and shielding others. By some of what he's said, his physiology reminds the Doctor of his own abilities. Not completely, but there are overlaps. None of that keeps the Doctor from worrying so he'll carry on in his way.

He's pleased he's finished the steak, though, and the Doctor gives him a friendly little nod and a smile. ]

Got it! Don't worry about you, no challenging you to a drinking competition, and for God's sake, never offer to pick your tab at the pub. [ A playful little smirk now. ] And if I read between the lines correctly, what you're also saying without saying is that I'd be daft not to pick you as partner for the first annual intra-factional relay race. Noted!

[ The Doctor reaches over to clear Steve's plate, and with his free hand, he offers it to the other man again. Sure, they shook hands a bit ago, but it seems a good way to part, given the way their conversation twisted and turned. ]

I'm glad we've met, Steve Rogers. You will absolutely be seeing me again, often. No taking it back now.