Minnesota United started Sunday's 4-0 victory over Real Salt Lake with striker Luis Amarilla and Ethan Finlay out with injuries that concern coach Adrian Heath, then lost captain Ozzie Alonso, who went down clutching his left leg, in the 18th minute in his return to the starting lineup.
Afterward, Heath said he believes Finlay has a knee meniscus injury about which "we fear the worst for the next four, five weeks."
Finlay will be evaluated further this week, as will Amarilla, who didn't play because of what Heath called "a little issue with his ankle" that has lingered for a couple of months.
"We thought he would get better, but it's not," Heath said. "It has been gradually getting worse. We'll have a better idea of a time frame for both of them [by Wednesday's game against FC Dallas]."
The Loons played on at Allianz Field with only one healthy striker, Mason Toye, who played the first 64 minutes before Jacori Hayes subbed for him. Raheem Edwards played up at that striker position for the game's final 20-plus minutes.
Hassani Dotson entered for Alonso. Heath said he will know more about Alonso on Monday.
"But if it's a hamstring, it doesn't look good for Wednesday or maybe next weekend," Heath said.
Alonso is 34 and playing in his 12th MLS season. He was signed before last season off waivers from Seattle, where he was an All-Star four times.