Manchester United close in on signing Marcos Rojo from Sporting Lisbon

Club sources are characterising the move for the Argentinean as "very complex". Yet once an agreement can be reached regarding if Nani should move to Sporting on a temporary basis - probably for a season - there is confidence at Old Trafford Rojo will become a United player and so strengthen an area of Louis van Gaal's squad that is particularly weak, according to theguardian.com .

As first reported last week by the Guardian the manager wants Rojo as he is a left-side defender who can play at centre-back and left-back.

Given Van Gaal's favoured 3-5-2 system the Dutchman requires at least one left-sided defender. Phil Jones, Chris Smalling and Jonny Evans, his three recognised first-team players in the position, are all predominantly right-sided.

If Nani does go to Sporting it will mark a return to the club he played two seasons for until 2007 before he moved to United. Despite flashes of brilliance the Portugal winger has failed to consistently deliver for the 20-times champions.

Rojo apologised on Sunday after refusing to train in an effort to push through the move. "I was hot-headed and I'm sorry. I'll be back with the rest of the squad tomorrow," he said.

"Sporting signed me when I was not at my best and gave me the opportunity to play for a big club in Europe. I would like to thank the trust they had in me and I will resume training on Monday."