Leicester manager Micky Adams has included a 24 hours call-back clause in Impey's deal should the Foxes boss want him to return before May.
Meanwhile, striker David Johnson completed 64 minutes of Forest's reserves fixture against Charlton on Monday night.
Johnson scored The Reds' second goal in a 3-2 defeat and is likely to be named as a substitute against Burnley at The City Ground on Wednesday night.
However, left-back Gregor Robertson came off after only ten minutes with what seemed to be a hamstring injury. With Alan Roger's suspension coming up, Joe Kinnear's options in that problem position seem to be central defenders Chris Doig, David Tarka or Des Walker after the club released Davy Oyen.
Forest youngsters James Biggins and Ross Gardner have been named in the England U19s squad to face Germany on 30 March.