West Bromwich Albion midfielder James Morrison could be out for up to six weeks after it was confirmed he suffered a medial knee ligament injury against Chelsea on Saturday.

The 22-year-old was felled by a challenge from Jose Bosingwa in the second half of Chelsea’s 3-0 victory at The Hawthorns and had to be replaced immediately.

However, he underwent a scan on Sunday and although he reported for international duty with Scotland ahead of their friendly against Argentina, he was sent back to Albion yesterday for further assessment.

Albion manager Tony Mowbray said it was too early to say how long Morrison would missing but he hadn’t yet ruled him out of this weekend’s trip to face Stoke City, although he warned if the injury was as serious as feared he could be out until the new year.

“Hopefully, it’s not too bad,” Mowbray said. “These injuries come in various grades and we’re not too sure how bad it is at the moment. The worse-case scenario is that he’s out for four to six weeks. The best-case scenario is that it’s just a tweak and it settles down in a few days. We’ll know more when he’s back from Scotland. We’ll do our own diagnosis on him.”

Morrison’s injury will mean he misses out on facing the South Americans in their first game under the leadership of Diego Maradona, but Mowbray hopes Morrison will be more gutted about missing the vital clash against the Potters at the Britannia Stadium.

“I would like to think that he would prefer to be fit for the weekend than for a friendly game for his country,” Mowbray said. “If he isn’t then we will both miss out.”

Bosingwa’s cynical challenge earned the Chelsea full-back, who had set the league leaders on their way to victory with a stunning strike, a yellow card but Mowbray refused to condemn the Blues star.

“It was just a normal tackle on a football pitch,” Mowbray said. “He caught him a bit late but so be it. I didn’t see anything in the challenge.”

Morrison isn’t Mowbray’s only injury worry. Defender Abdoulaye Meite was taken off in the 69th minute on Saturday as a precaution after his 11-week lay-off because of a calf injury, and goalkeeper Dean Kiely has been sent back to Albion from the Republic of Ireland squad because of a wrist injury.

“Abou had only had one week’s training,” Mowbray added. “The game was finished and there was no point in risking his calf, which can be affected by fatigue.”

Despite the returns of Morrison and Kiely, Mowbray still has several players on international duty and unlike other managers such as Aston Villa boss Martin O’Neill, who has questioned the point of the fixtures, Mowbray has no complaints.

“I have no issue with them,” he said. “It is the same for everyone, especially in the Premier League. We generally all have international players and while I would suggest that most managers would prefer to have full squads to prepare for the weekend games, we are in the same boat and we have to accept it. Fifa regulations suggest they have to go and so we have to get on with it.

“We have six away and it is part of it. Up at Old Trafford they could have 28 away and I am sure Stoke will have players away”