Gareth Bale is not having the greatest of times at Real Madrid, encapsulated by the poor outing he endured in the El Clasico on Saturday, where he was substituted on the hour mark for Karim Benzema.
Seeing the struggles that Bale is enduring in La Liga, Manchester United are reportedly monitoring the situation with a view to a possible summer bid, according to British newspaper The Sunday Times.
Bale moved to Madrid for a world record fee of £85 million - much less according to Los Blancos president Florentino Perez - from Tottenham this summer. However, with a lack of preseason and a few niggling injuries, Bale has failed to set the Real world on fire, and questions have been raised over the signing.
United had reportedly made a bid for Bale in the summer transfer window, only for the Welshman to reject the move as he had his heart set on a switch to Madrid.
However, if matters fail to improve for Bale, he could conceivably look at a return to the Premier League, where he was easily one of the league's leading lights.
United will be waiting in the wings if such a situation arises, particularly with the club keen to make amends for a disappointing summer window, which saw only Marouane Fellaini - for £4 million more than was necessary - coming into the side.
Public pursuits of Cesc Fabregas, Leighton Baines and Ander Herrera failed miserably, with chief executive Ed Woodward insisting the reason for the failure was because of new management at the club and the loss of both Sir Alex Ferguson and David Gill at the same time.
"With Fabregas that was an approach specific to the selling club," Woodward told fanzine United We Stand. "They have an ownership structure that means there has to be debate before a player is sold.
"It was disappointing that we didn't sign more players, but I always knew it was going to be a tough window. We didn't want to impose a plan on the new manager that had come from the old manager... and we knew we had a truncated window.
"The early view was that we needed a central midfielder and a left-back, but David also wanted to spend time with the squad. There wasn't a long list he wanted -- it was a unique window."
Woodward, though, said he was happy to have kept Wayne Rooney at United despite the overtures from Chelsea. "The Rooney situation was another unique one," he added. "It was important that we made our position very clear. I am delighted he is still wearing red. He is irreplaceable and phenomenal to watch."