Sir Alex Ferguson has slammed Kevin Davies for the tackle that left Manchester United midfielder Tom Cleverley with a broken foot.
Cleverley left the Reebok Stadium with his foot in a protective cast after being caught in a tackle by Bolton skipper Davies.
Even Cleverley fears the worst, which comes at a bad time given the 22-year-old has just broken into the England squad.
The injury cast a shadow over United's ruthless 5-0 triumph and left Ferguson biting his lip.
"We think it is a broken foot," said Ferguson. "It is unfortunate but we expected it. It was a bad tackle."
Davies was not cautioned for the incident but shortly afterwards picked up his 100th Premier League booking for felling Patrice Evra.
If the worst is realised, Cleverley can expect to be out for around three months.
The injury did not prevent United maintaining their sensational early season form, with Wayne Rooney becoming only the fourth player in Premier League history to score hat-tricks in back-to-back games.
It took Rooney's tally onto eight for the season, more than 18 Premier League clubs have so far managed, the exceptions being United and Manchester City.
It is a far cry from Rooney's poor form of 12 months ago, with Ferguson believing the trigger has been his number one striker's new-found maturity.
"When players get to their mid-20s, there is more thought in their game," noted Ferguson.
"Their timing is better. Wayne's presence is good and he is looking fantastic."
Rooney was joined on the scoresheet by strike partner Javier Hernandez who marked his first start of the season with two goals and Ferguson was full of praise for the Mexican.
"Hernandez's movement, speed, imagination and presence within the game was terrific," added Ferguson.
"He is a menace to any defender. Over the years the second season for players can be hard. But I never had any doubts."
Meanwhile, Ferguson will check on the fitness of Patrice Evra, who took a blow to the knee, before finalising his squad for Wednesday's UEFA Champions League encounter with Benfica in Lisbon, although he expects to be without Jonny Evans, who was forced off with a hip injury.