Thorne, 19, has joined Posh on loan from West Brom until the start of January and manager Darren Ferguson seems keen to pair him up with the experienced Grant McCann in the centre of the park.
Ferguson signed Bostwick from Stevenage in the summer for a fee in the region of £800,000 and the Posh boss admits he has been thinking about playing him at the back for some time.
"I've been considering it for a while and George's arrival will now allow us to put Michael Bostwick in at centre-half," Ferguson said.
"I know midfield is an area that we have got numbers in, but I think George offers something slightly different.
"It frees up more options for me because I think we need another centre-half and this allows me to utilise [Bostwick] there. That was a big attraction to me."