Leicester have had a bid accepted by Birmingham for Demarai Gray, Press Association Sport understands.
The January transfer window only opened on Saturday but Leicester, who begin 2016 level on points with Barclays Premier League leaders Arsenal, have moved quickly to follow up their interest in the highly-rated teenager.
During the summer the Foxes triggered a release clause in Gray's contract but the winger decided to remain at St Andrew's.
Now though, an offer thought to be around ?3.75million has led to the 19-year-old discussing personal terms with Leicester and undergoing a medical.
Bournemouth, Leicester's opponents on Saturday, were also interested in Gray and had several bids for him turned down in the summer.
Gray was not in the Birmingham squad for their Sky Bet Championship fixture at home to Brentford.
It is hoped his move to the King Power Stadium will be concluded next week, with the possibility of the deal involving a loan back to Birmingham for the remainder of the season.