Let him continue to play without pressure. He may be capable of becoming a good captain. But playing good is not enough to be a captain.
Let him get more matured and consistent as a player.
Captaincy can't be used as a gift. It puts a lot of pressure on a player, got to remember that as well.
[Post CWC15 Consistency Record: Test: W-0 L-0 D-0// ODI: W-3 L-0 // T20: W-1 L-0]