Ashley Williams is feared to have suffered a cracked rib after being taken to hospital during Wales’ 0-0 draw with Mexico in California.
The Everton centre-back suffered the injury 17 minutes into the game at the Rose Bowl in Pasadena.
Williams suffered the injury stretching for the ball and was clearly in pain as he was led from the field with Aaron Ramsey taking over as skipper.
Manager Ryan Giggs said: ”He’s gone to the hospital to get an X-ray.
“He’s gone to check that there’s no real damage, maybe just a cracked rib.
“They’re really painful. You breathe, you sneeze, you cough – it’s agony.
“Fingers crossed he’ll be okay because we want him fit and back for pre-season.”
Wales – without Gareth Bale after his Champions League heroics with Real Madrid – earned a creditable draw against a Mexico side preparing for the World Cup in Russia.
Keeper Wayne Hennessy denied Jesus Manuel Corona, Javier Aquino and Hector Herrera to keep an inexperienced Wales side in the game which was watched by around 80,000.
Giggs added: “It’s a clean sheet against a very good team.
“The next part now is to show our quality, because we can do better in the final third.
“We were not rewarding the way that we were defending and the way that we had worked. So that’s the next step.”
Chris Mepham, Brentford’s 20-year-old defender, impressed on only his first start while Giggs also handed debuts to George Thomas and Matt Smith.
Giggs added: ”I’ve learned that we’ve got quality in depth,” Giggs said. “We’ve young players who, if they’re given a chance, they’ll take it.
“That’s what I want. I want competitiveness between the squad, where we’re not just picking 11 or 12 players.
“We’ve got a lot out of the last couple of weeks and it ended with a magnificent test against a very good team.”