Could that be James Rhodes
A.K.A. War Machine, who was injured during Captain America: Civil War?
Iron Man recruits his pal «Rhodey,»
a.k.a. War Machine (Don Cheadle), Black Widow (Scarlett Johansson), Vision (Paul Bettany), plus the new Black Panther (Chadwick Boseman)-- the son of the slain Wakandan king — and a new Spider - Man (Tom Holland).
Part way through the trailer, there's a shot of Tony Stark cradling his friend James Rhodes,
A.K.A. War Machine as the latter lies unconscious in his battered armor.