Ben Chilwell cut a forlorn figure at the final whistle as Chelsea beat Dinamo Zagreb 2-1 in their final Champions League group game.
The England left-back clutched his hamstring and fell to the ground in stoppage time at Stamford Bridge to cast huge doubt over his chances of making it to the World Cup in Qatar.
Asked about whether Chilwell’s injury would mean he would not be available for selection by Gareth Southgate, Potter said: “I think you would have to say so, yeah.
“Obviously I don’t want to add any more than that but when a player pulls up like he did and he felt it so it’s never positive.
“I spoke to him briefly. He felt something as he was setting off so he’s disappointed and he’s upset. It’s not positive at the moment.
“It’s a blow to see him pull up like that. It’s not a great sight so fingers crossed when we get it scanned it isn’t as bad.”
Having received treatment, Chilwell was helped from the pitch and consoled by Mason Mount who asked what had happened.
And the lipreaders reckon Chilwell told Mount “it’s popped”, leaving Mount upset for his club and international teammate.
The left-back was on crutched at full-time and although he will be waiting for a scan to reveal the true extent of the problem, it’s now very unlikely he will be on the plane to Qatar with the World Cup less than three weeks away.
It’s a devastating blow for Chilwell, who failed to play a single minute in England’s seven matches at Euro 2020, before a rupture of his ACL last November kept him out of action for five months.
On the win against Zagreb – who beat Chelsea on matchday one in what proved to be Thomas Tuchel’s final match in charge – Potter added: “Really pleased. Not the ideal start for us but the character was good and overall we played quite well.
“We attacked well, had some good chances and finished it off in a positive way.
“Whenever we have played Raheem Sterling we try to get him as high as we can.
“He has only ever needed to defend against the full-backs so it was a slight change in terms of the back four behind him but not too much change.
“The worry would be if you are not creating chances. Tonight we had a few we could have scored obviously. But our intent was good, our play was good and there is always ways to improve but the quality was there.
“We got the win, a performance and the boys gave everything.
“We are a work in progress but with our Champions League campaign we can be happy.
“We dust ourselves down for a big game on the weekend.”