He's got me worried a little right now, too. The shoulder is a concern because it looks like something that won't put him on the DL but it could sap his power all year if he never gets to 100%. Yeah, he's not a homerun hitter, but he was increasing his HR totals his first three years and his 15 last year is a good total for a speedster-- certainly a lot more than you'll get from Freel, Pods, or Pierre.
My other concern is that his steal attempts are down this year. This trend started the second half of last season. That might be good for the Rays in real life, but I want aggressiveness for my fantasy team.