Manchester United striker Marcus Rashford has reportedly managed to put on 4kg of muscle following his recent shoulder surgery.
But while adding muscle, he lost mass in his upper body while mobility was reduced after the operation.
And United want him to bulk up as soon as possible to protect him from further injury.
The Red Devils would like the striker to add protein to his diet to help build back his overall weight.
The belief is he will then have a better chance of withstanding Premier League demands.