Trippier has been heavily linked with a return to Premier League football despite playing a key role in Los Rojiblancos La Liga title win in 2021.
United are tracking the England international with growing interest but a recent shoulder injury for the 31-year-old has complicated their ongoing pursuit of him.
Atletico have not put an expected return date on Trippier’s rehabilitation but initial reports have hinted that he could be sidelined until at least the start of 2022.
According to reports from the Manchester Evening News that situation could line up perfectly with a January swoop for the former Tottenham defender.
United and Atletico are likely to haggle over a transfer fee in the region of €35m to secure a deal, with Portuguese international Diogo Dalot set to be offloaded, to free up a squad place for Trippier at Old Trafford.