Manchester United midfielder Tom Cleverley will anxiously await the results of a scan that will determine whether his career has been stalled yet again.
Cleverley was one of the inspirations behind United's flying start to the season, only to suffer a foot injury at Bolton in September that ruled him out of action for six weeks.
The 23-year-old's comeback lasted just two games before he was sidelined again, this time with an ankle injury that proved far more long-lasting.
After almost four months out, Cleverley returned in Amsterdam last week and then kept his place for the return Europa League tie with Ajax at Old Trafford last night that almost ended in a calamitous exit.
Although there was no obvious sign of a problem when Cleverley spoke after the game, and indeed, highlighted his delight at being called into Stuart Pearce's England squad for the friendly with Holland, it now transpires he was suffering a problem.
"He got a knock," Ferguson told MUTV. "He has been sent for a scan but we don't think it's serious."
If Cleverley was ruled out it would be a grievous blow for player and club.
Unusually for a player with such limited experience, Ferguson has wasted few opportunities to outline just how much the midfielder's energy was being missed.
Undoubtedly he would have been handed his international debut by Fabio Capello had the August friendly with Holland not been postponed and then injury denied him a call-up for the matches against Spain and Sweden in November.
He was expected to play some part at Wembley next week and, speaking after last night's game, revealed how much he was looking forward to it.
"It is a massive thing," he said. "I have only played two games, so to get another call-up is fantastic for me and my family.
"I have been lucky. The manager (Pearce) knows me well from the Under-21s. Hopefully I will impress him."
Cleverley also felt it would be another step towards full fitness after such a long time out.
"I managed to get another hour under my belt," he said.
"I am buzzing now. I had a great start to the season and I have worked tirelessly with the physios to get back in shape."