​Manchester United defender Luke Shaw could be fit to face Watford at the weekend, just one week after suffering concussion in England's Nations League loss to Spain.

Shaw clashed with Spain's Dani Carvajal and was stretchered off in the 53rd minute after supplying the assist in the first half for Marcus Rashford's strike.

​According to ​BBC Sport, Shaw could play after being treated in United's "enhanced care setting", although FA guidelines state a player should not feature for their team for at least 14 days.

England v Spain - UEFA Nations League A

The guidelines allow a player to return earlier than the recommended time span if seven criteria are met, as outlined by the ​FA's website, and the Red Devils' modern medical facilities are thought to meet requirements.

It means United's medical staff must be certain of the former Southampton defender's recovery before making him available to manager Jose Mourinho, who was in attendance for the Nations League tie.

​United's website hinted on Wednesday that Shaw may not be available, stating: "Jose Mourinho could be without Luke Shaw, who sustained a head injury in England's UEFA Nations League match against Spain at the weekend. 

England v Spain - UEFA Nations League A

"Some reports suggest the left back will be obliged to serve a mandatory seven-day concussion period of absence, though this has not been confirmed."

Shaw has started the season brightly for ​United, featuring in all four of their opening Premier League matches and scoring once in the 2-1 victory against Leicester on the opening day.

In Shaw's absence Tottenham left back Danny Rose started against Switzerland in a 1-0 win at the King Power Stadium in Leicester.