Louis van Gaal is said to be open to letting Anders Lindegaard leave.
The Dane has played second fiddle for most of his four seasons at the club, and wasn't even on the bench as United kicked off this year's Premier League campaign with a loss at home to Swansea. He was this week linked with a move to Portuguese giants Benfica.
It is rumoured that Van Gaal rates 24-year-old Ben Amos ahead of the former Aalesund man, and the Englishman has started the season as back up to undisputed first choice David de Gea.
Lindegaard has made just 28 appearances for United since joining in 2010, and struggled for any game time at all last season as he played just 3 games under David Moyes and Ryan Giggs.
Celtic recently sold England international Fraser Forster to Southampton for £10 million, and though they have former Scotland international Craig Gordon at the club, there will certainly be doubts regarding the former Sunderland man's fitness after he only recently came out of retirement.
With fellow Scandinavian Ronny Deila in charge at Celtic Park, Lindegaard would have access to much more regular football in Glasgow while the Scottish champions monitor and improve Gordon's fitness.
Whether Van Gaal dips into the transfer market to reinforce his goalkeepers should Lindegaard depart will depend on just how much confidence he has in Amos, after this summer criticising the player for failing to save Miralem Pjanic's long range effort on United's US tour.