Juan Mata-Angel Di Maria
Juan Mata-Angel Di MariaGetty

Former Liverpool striker Stan Collymore believes the arrival of Angel Di Maria at Manchester United would raise questions over Juan Mata's future at Old Trafford.

The 26-year-old arrived from Chelsea on a £37.1m deal earlier in January. Even before his career could take off with the 20-times English champions, change of managers at United saw him being linked away from Old Trafford during the summer transfer window.

Meanwhile, Di Maria was signed by the 20-times English champions for a British record fee of £59.7m from Real Madrid. The arrival of the Argentine international has seen Mata being linked away from Old Trafford.

The Mirror reports United manager Louis van Gaal wants to sign AS Roma midfielder Kevin Strootman in January and wants to include Mata as a part of the swap deal.

"Juan Mata is the most likely to feel the pinch after the arrival of Di Maria and he may well think he has been sold down the river by the club or, at the very least his former manager David Moyes, having only joined United from Chelsea in January," Collymore told the Mirror.

United also signed Radamel Falcao on loan from Monaco on deadline day and have an option to make the deal permanent at the end of the season. Collymore says Van Gaal would not hesitate in dropping Dutch international Robin van Persie from the starting XI if he fails to remain fit throughout the season.

The 43-year-old former striker claims the 63-year-old manager could start with Falcao and skipper Wayne Rooney to lead United's attack, despite Van Persie playing under Van Gaal during the World Cup with the Netherlands.

"And even though there were hugs and high fives between Van Gaal and Van Persie with Holland during the World Cup, I still think the manager is so ruthless that he could go with two up front and make Rooney and Falcao his first-choice duo," the former Reds man said.

"There are concerns about Van Persie's injury record and the fact he seems to self-diagnose, only playing when he feels one hundred per cent fit, and United need all hands to the pump if they are to get back into Europe."

"Of course, so much will ­depend on whether Van Gaal sticks with a back three or whether he changes the shape from 3-5-2 to a 4-3-3 or, as I would, a 4-2-3-1 formation," Collymore concluded.