Jose Mourinho has admitted a rejuvenated Anthony Martial is winning his trust again after emerging from last season’s slumber but the Manchester United manager left Luke Shaw in little doubt that the defender has considerable work to do to force his way back into his first-team plans.

Mourinho’s warning at the end of last season that the “fragile” players in his squad must toughen up if they want to retain his faith appeared to be a thinly veiled ultimatum to the likes of Martial and Shaw, both of whom endured disappointing campaigns.

Martial endured an acrimonious break-up from his former partner, Samantha Jacquelinet last year, which is thought to have contributed to his drop in form after a blistering debut season at Old Trafford, but he is now in a happy relationship and people around the club have noticed a spring in his step.

“I see a great improvement in the person, in the mood, in the face, in the body language – if you want just a word, in his happiness,” Mourinho said of Martial ahead of Saturday’s game at Southampton. “I am very pleased with his attitude overall and then it’s easier to play well. He’s improving a lot – not just on his will, his desire to do it, but being effective on that.”