According to transfermarkt he has only played ~1000 minutes this season, compare this with Falcao (1300), RVP (~2000), and Rooney (~3000).
So less gametime than any of our three main strikers (Rooney is a bit of an exception as he has played midfield as well, of course). If we had him as our second striker next year, that would mean he should be guaranteed at least 2000+ minutes over the season I reckon, which I think is a fair amount for a player of his quality.
I would much rather take him as second striker than see him go to another PL club - he can be a great impact sub, a good foil/partner for Rooney, and provides some pace up front which we have sorely lacked this season.