This is really risky for him. He has a higher probability of truly making it if he stayed at Milan and tried to continuously up his level until he moves to a big club with a vacancy at LW. I'd love for Gerard to make it here, but it's just difficult. He could own the LW position and have a club build their attack around his dynamism if he grows into even 3/4 of the player he promised to be. Instead he opts to come to Barca for, at best, a 50/50 shot at holding down a 4th fiddle position to MSN on his weaker flank.
He is far better than any of our options currently though. From the club's perspective, it's a cheap acquisition for a versatile player who can make a difference on either wing and as a supersub. If he doesn't work out, they can dispose of him elsewhere without a second thought. It's Deulo's career that's being gambled with, and only he will really suffer in the long term if this transfer doesn't work out.