With SMS there is a chance, I think. He could more than tripple his wages here and he'd be a guaranteed starter. He plays for a club that would obviously jump at the chance to sell him for a huge fee, and there's nothing that guarantees Lazio will be more likely than us to qualify for Champions League at the end of next season. He has already stayed there too long and probably needs to move this summer.
Other big clubs are mostly well stocked on players in his positions too. Juventus or Real Madrid would be the obvious destinations realistically, but I think both of them will be busy in the foreseeable rebuilding other parts of their starting elevens. Juve already bought Kulusevski too. SMS is the wrong fit for Liverpool, and Chelsea and United have already sorted out their midfields. There could be an opportunity for a club like Arsenal to come in. Signing him is not less realistic than signing Özil in 2013, or signing Pepé last summer. It's mostly about being willing to pay the market price. We've never done that historically, but last summer we showed we're willing to do it. I don't think one so-so experience should discourage us from doing it again. We'll get it right more often than not as long as the player fits into the team we want to build.