I certainly can't see Hughes playing him as any kind of winger/wide player, but as Rob says, he might have plans to play him as one of 3 central midfielders. Hasn't Hughes gone for a 4-1-4-1 (or similar) shape? If so, Chalmers might be one of those three players in the middle. We have Thomas, Dow and Lawless as wingers, surely Hughes hasn't signed Chalmers as a fourth.
That's where the 4-1-4-1 shape might come in. There's been a suggestion that Hughes might want Dorrans playing almost as a number 10, so we could have Chalmers in front of the back 4, with any two of Pybus, Todd and Dorrans in the middle, with Pybus as the ball winner, Chalmers to keep possession and Dorrans to create chances. I still don't see exactly what Todd offers in there but he's starting every week. Sounds like Allan needs to win his spot in the starting 11 again.