CELTIC star Liam Miller is being tracked by Manchester United. The 22-year-old midfielder is out of contract in the summer and talks between Martin O'Neill and Miller's agents Finton Drury and Eamonn McLaughlin have been inconclusive. O'Neill is desperate to tie up the Republic of Ireland star. And aware of growing interest in the player, he asked the agents in for nitty-gritty talks after Miller's outstanding display against Belgian side Anderlecht in the Champions League match at Parkhead 11 days ago. Sir Alex Ferguson attended that game to watch Anderlecht defender Vincent Kompany but was aware also of Miller, who has burst on to the scene this season. Mail Sport understands Fergie is likely to make his interest official in the New Year. The fact he can sign the player in the summer under freedom of contract a small compensation fee might have to be paid adds to the attraction. Miller will have a good deal of soul-searching to do and advice to seek in the coming weeks. He wants to be loyal to Celtic and knows he's now virtually guaranteed a first-team start every week which is unlikely to be the case at Old Trafford. But as much as he's enjoying life at Celtic he knows he might not get another chance to play alongside boyhood idol Roy Keane. That lure could prove hard to resist. However, O'Neill will make sure Celtic offer him a lucrative long-term contract to tempt him into staying. The Celts boss had hoped to have Miller signed by the end of this month but that's now unlikely as the player weighs his options.