The phrase "next captain" refers to the person who will lead or be in charge after the current leader. It signifies the future successor or the person who will take on a leadership role in the future. Full definition
Marvel's next Captain America installment will go head to head with Zack Snyder's Man of Steel sequel. (themarysue.com)
I do nt think we have many who jump to the forefront when contemplating next captain but i believe Ramsey is a better choice than the much heralded Wilshere. (justarsenal.com)
Sebastian Stan had a different take on the «next Captain America» question when it was posed to him at the con. (cbr.com)