The Blues star has joined Forest on loan for the remainder of the season, with the intention of rebuilding his match fitness.
Having spent much of the current campaign battling tendonitis in his knee, the 26-year-old has welcomed the opportunity to gain regular first-team action at the City Ground.
While getting back to his best remains his sole focus at present, with only a year left to run on his contract at St Andrew's, McSheffrey admits he may yet be persuaded to extend his stay on Trentside.
"The deal is to the end of the season, although Birmingham have an option to call me back," he told the Nottingham Evening Post.
"So it could be four weeks, it could be eight weeks, it could be to the end of the season.
"Who knows? I have a year left on my contract at Birmingham, so I am in no rush to make any decisions.
"What this does is give me a chance to have a look at the club and, likewise, Forest a good chance to have a look at me.
"I will have to cross the bridge when it comes to it. We will see what the manager says, first and foremost."