Manchester United have taken the option to extend the contracts of Juan Mata, Ander Herrera, Ashley Young and Daley Blind until 2019, according to latest reports.

All four were set to be out of contract at the end of the 2017-18, season but United have now confirmed to the players that 12-month extension clauses included in their contracts are activated, according to the Daily Telegraph.

While United are no longer facing the possibility of the quartet leaving on free transfers at the end of the season, the futures of Mata, Blind and Young are still uncertai,n with Mourinho yet to make a decision on their long-term roles at the club.

United also took the decision to trigger a 12-month extension option in Luke Shaw's contract earlier this season, saving the club from the prospect of losing him in the summer and giving Mourinho more time to decide on his future.

Mourinho now has a number of big calls to make in how he shapes his squad over the next 12 months. Blind, who reportedly remains on Barcelona's radar, has been a useful squad option for his manager this term, having started every game in the Champions League group stages in a number of different positions. However, he has been limited to just three starts in the Premier League.

Young, meanwhile, has emerged as the club's first-choice left-back in recent months and has provided cover at right-back in Antonio Valencia's absence. But turning 33 this summer, it remains to be seen if he will feature in Mourinho's plans when reinforcements in full-back positions arrive.

Mata, who arrived at the club from Chelsea four years ago, has shown his worth once again in recent weeks, scoring twice against Leicester City. He recently suggested he would like to follow in the footsteps of Ryan Giggs and play for the Red Devils into his 40s.

While the immediate futures of those four and Shaw have been resolved for the time being, the club are now facing a battle to hold onto Marouane Fellaini. United triggered a 12-month extension clause in his contract this time last year but efforts to tie the Belgian down to a new deal have so far proved fruitless. Besiktas are currently seen as the favourites to sign the midfielder when his deal in Manchester expires in June.

Ander Herrera and Juan Mata
Mata and Herrera are among the players who have reportedly seen their contracts extended by 12 months. Getty