When you consider how little Kompany has played this season as 4th choice, I see no reason why Garcia can't take up that spot when Vinny leaves. There is little risk, bar an injury crisis, and even then from what we have seen from Garcia, he looks very assured and a big talent. Kompany's hardly set the world alight in his limited performances this season, and that hasn't affected us. Garcia's performances have been mature and looks like a player beyond his years, which is rare to see in such a position in my opinion.
These are the situations where all I want the club to do is take a punt on a youth player instead of going out and buying someone for £30m to play 15-20 matches a season. We have 3 excellent CB's, give the lad a chance and we may reap the rewards of it. If it doesn't work out, we can always dip into the market, but we'll also find ourselves in a situation where Garcia's value will have been upped significantly as a squad player for City (see Zinchenko).
Pep loves to big academy stars up, but judging by his comments on Eric's injury (keeping him out for 2 months), it sounds like he may have been more involved in the setup. I feel like he's shown enough to be considered for a few more games this season - certainly against weaker opposition, and with Kompany's injury and the Christmas period coming up, there may be some opportunities for him, especially after his excellent performance.