U.S. men’s international Christian Pulisic is doubtful for Chelsea’s English Premier League match at Southampton Saturday, according to manager Thomas Tuchel.

The midfielder has some calf issues.

“It’s nothing big,” Tuchel said during a Friday press conference. “It just feels tight and a bit of a risk.”

Tuchel added that he and the team was not concerned or worried but the medical department is on that.”

“Now we have some little issues in the calf and he stopped training yesterday before it became an injury so I would not say that it is an injury at the moment,” he added. “It’s risk management that relates to his history of having injuries so we do not want to enter in the same cycle.

“It’s sometimes like this and the main thing for Christian is to stay positive, keep his head up and be ready because he can have a big impact when he starts and he can have a big impact when he comes from the bench with his intensity.”

Tuchel then gave Pulisic a vote of confidence, even though he hasn’t started or played the USMNT player that much since he took over for the fired Frank Lampard.

“Chelsea bought Christian for a reason, for his quality and his potential so it’s our job to bring out the best in him,” he said. “He proved in many weeks that he has the level to be a Chelsea regular player, to have a big impact at this club and it’s a challenge now to maintain the level and to keep improving.”