Sgarbossa only has 16 NHL games played and this therefore considered a prospect. I think you may actually have some prospect slots open (you're currently allowed a total of 27 combined between your main and prospect rosters), so this add is theoretically fine, but I wanted to flag it up in case you weren't aware or the IR replacement add rules. You would also need to post Sgarbossa in the Add/Drop Prospects thread, rather than this one.