Yes, look at where you are going to be missing having him coming up, and consider if he is good enough (he looks like he might be) to hang onto.even if you have to play guys out of position to keep him. He is young, so think in terms of how long you expected to have him on the Team.

On my main Team I buy Tokens, but still only heal when I have to (unless it's Bobo). On my little Teams, it's do I sell or no. And there can be MUCH longer injuries. Worst I've had my Team was a 20 day broke leg (maybe it was ankle..) The shorter term injuries I try to get away without healing, or take a day off if it's a key guy. The things is, 15 is the most packs you ever have to use, so even a 20 day injury can be healed thus.

The upshot is how much does he contribute to your team.. .