Manchester United have triggered the option to extend Ander Herrera's contract, which will keep the Spaniard at Old Trafford until 2019.

Herrera's current deal was due to expire at the end of the season and Atletico Madrid had been monitoring the midfielder's situation, who instead opted to commit his future to United. Herrera's representatives remain in talks with the club over a longer deal, but United's decision to trigger the 12-month extension, according to The Daily Mail, means they will not run the risk of losing the former Athletic Bilbao man for free.

The 28-year-old has endured a difficult start to the season, slipping down the pecking order following Nemanja Matic's arrival in the summer and regaining his place in the starting XI only after Paul Pogba suffered a hamstring injury that kept him out for almost two months.

However, Herrera and Matic struggled to provide the same dynamism and with Pogba returning to the starting line-up over the weekend, Herrera found himself on the bench again.

The Spaniard won the club's Sir Matt Busby Player of the Year award in May and was voted man of the match in their Europa League final win over Ajax.

Herrera is not the only United player who has less than 12 months left on his deal and the Telegraph reported last week that United were looking to secure the immediate future of a host players by invoking a 12-month extension clause in their current deals, with Mourinho eager to stop them from leaving for nothing after the end of this campaign.

However, while Ashley Young, Daley Blind and Juan Mata are expected to pen extensions, there are concerns Marouane Fellaini might leave either in January or in the summer.

Mata and Blind have failed to feature regularly this season, with the duo making 11 starts in the Premier League between them this season, while Young has featured in the left-back position ahead of Luke Shaw, Matteo Darmian and Blind. The England international will be 33 next July and is not seen as a long-term player in that position at United.

Fellaini, meanwhile, looks increasingly likely to leave Old Trafford at the end of the current campaign amid interest from Turkish giants Galatasaray and Besiktas and La Liga outfit Valencia.

The Belgian has established himself as an important part of Jose Mourinho's plans after a difficult start to his career on the red half of Manchester and has proved to be an extremely useful option from the substitutes' bench so far this season.

Galatasaray almost signed Fellaini in the summer, but their attempts to prize the gangly midfielder away from Old Trafford were stopped by Mourinho, who will hope United can thrash out an agreement with his towering lieutenant in the coming months.

Besiktas are another side who were sniffing around Fellaini, and club official Metin Albayrak revealed that the versatile midfielder is one of a number of players the Turkish giants are targeting.