Bournemouth boss Eddie Howe admitted things did not look good for Callum Wilson after the Cherries' top scorer was carried off on a stretcher having suffered a knee injury early on in the 2-1 loss at Stoke.
Wilson went down under a challenge from Philipp Wollscheid in the eighth minute of the game at the Britannia Stadium.
Having had treatment on the pitch he appeared to walk it off and came back into the match, but moments later the five-goal striker was back down, his leg having buckled as he ran, and he subsequently departed once again on a stretcher.
Howe - who has already lost Tyrone Mings and Max Gradel to serious knee injuries this season - said: "It doesn't look good at this moment in time.
"He is in a brace and on crutches and is in a bit of pain - there is a bit of swelling there.
"We won't know until we get it scanned and properly looked at, but it is worrying for us - it looks like it could be another serious knee injury.
"All I know is he took a whack to the knee, felt he was okay to carry on and then collapsed in agony, and obviously that is not a good sign.
"With joint injuries you have to be so careful and it looks like it could be a serious one. It was a huge blow for us right at the start of the game."
Asked about the decision that saw Wilson briefly back on the field, Howe said: "I think Callum felt his knee was okay at that stage, and you are really in the hands of the player - he wanted to carry on, such is his nature.
"The physios were obviously aware there could be a potential injury there and they relayed their concerns to him, but he felt he was strong, able and fit enough to carry on.
"Obviously that wasn't the case, and it was a real key moment in the game."
With Bournemouth still looking a little shell-shocked from the Wilson situation, they fell behind in the 32nd minute via Jonathan Walters' close-range finish.
They hit back after the break through Dan Gosling's 76th-minute equaliser, before Stoke substitute Mame Biram Diouf headed in the winner with seven minutes to go.
Howe felt his side had not reacted well to Wilson's departure, but praised their second-half effort and claimed a free-kick awarded against them in the build-up to Diouf's goal had been given incorrectly.
"Glenn Murray used his body and protected the ball really well, but the referee (Lee Mason) has given a free-kick," Howe said.
"When the opposition scores 20 seconds later, it is a big moment. So we have been on the end of a poor decision - but having said that, we could have defended that situation a lot better."
The result was Stoke's first Barclays Premier League victory of the season and saw them move out of the relegation zone.
Potters boss Mark Hughes said: "It was an important win.
"I would argue we have probably played better in other games and got beaten. But today was about getting the three points and making sure we got that situation we found ourselves in off our backs.
"We are delighted with the result and will take the three points."
Hughes had injury concerns of his own, with winger Xherdan Shaqiri having been forced off after picking up an apparent hamstring problem just before the interval.
And the Stoke manager said: "I haven't had an update yet. It looked like a hamstring - he pulled up sharply.
"We'll settle him down tomorrow, probably get a scan on Monday and see what the damage is. But hopefully - given he came off quite readily and didn't hang around - he hasn't done too much. He did the right thing."