Which Colts Offensive Player has the Most to Prove in 2018?

Mewhort according to this article
The Colts have plenty of players who need to prove themselves next season, but who on offense needs to do it the most?
The Colts have a lot of new faces in their organization. Some of them are in the locker room too. But there are plenty of old faces who need to prove themselves, and plenty of them play offense. But who needs to prove themselves the most?