Sturridge is the most talented player at the club. If we can get him fit, he'll score goals. There are no ifs or buts with most of the rest of the players - they simply aren't good enough, even when fully fit.
You could suggest selling almost any other player - bar Coutinho, perhaps, and it'd hardly concern me at all. The rest are all mediocre and fully replaceable.
To me, we'd be kind of selling Sturridge to punish him for being injured. I get the frustration but where's the logic? I'd rather have Sturridge for twenty games in a season, than have him at a rival club.