It won't happen but if the deal was right I'd take him back. He's not become a bad player over the past couple of seasons, he's just had some terrible luck with injuries and has been a victim of the madhouse that Barca have become over the last few seasons. His last 18 months for us were outrageous, averaging a non penalty goal or assist every 95 minutes in the PL and CL. If you could get a third of that output from him you'd have a player.
He's somebody that thrives on being the centre of a side though (and why he's struggled at Barca with Messi around) - he's made for a side like Spurs or Arsenal, where he'd be the main man.