It's Toronto FC's worst nightmare.
When the Canadian club hosts Chivas USA on Wednesday night, it will take to the field without influential playmaker Dwayne De Rosario.
Acquired by Toronto in an off-season trade with the Houston Dynamo, De Rosario sat out practice last Friday as a precaution before aggravating a hamstring injury in Sunday's 3-2 loss to FC Dallas.
Toronto coach John Carver confirmed Tuesday that De Rosario, a native of Scarborough, Ont., is scheduled to have a scan to determine the extent of the injury and will miss two games and could be out even longer.
"He's definitely out for two [games] and it might be more than that," said Carver.
"I think building up to the game on Sunday, it was an issue of he just had a tight hamstring. You saw from his reaction he did tear it. To what degree, we're going to find out once he has a scan. But he has a tear in there and that can be anywhere [from] three to four weeks."
Carver said the team will take a conservative approach with regard to De Rosario's recovery and won't rush him back into the starting lineup.
"I won't put him under any pressure to get him back, although I could do with him on the pitch," Carver said.
Indeed, the loss of De Rosario, a three-time all-star, is a big blow to a Toronto team that won its first game of the 2009 Major League Soccer season, but is winless (two losses, two ties) in its last four contests.
Any prolonged absence would be detrimental to Toronto's playoff hopes. The Canadian club acquired the veteran midfielder to help it make the post-season for the first time since entering the league in 2007.
The loss of De Rosario coincides with the arrival in town of Chivas USA, the best team in MLS with a 4-1-0 record.
While Toronto is still stinging from Sunday's loss in Dallas, Chivas is coming off a 2-0 win at home over the Seattle Sounders and is unbeaten in five games, its longest unbeaten run in club history.
Toronto's next game is Sunday evening at home against the Kansas City Wizards.