Right back Tony Beltran gingerly put weight on his right leg as he limped to the locker room, supported by RSL striker Yura Movsisyan and head trainer Tyson Pace.

As they made their way down the sideline play resumed, but Beltran’s season may not. He suffered an unspecified knee injury in RSL’s 1-0 loss at Colorado on Sunday.

RSL coach Mike Petke said after the match that he did not have an update on whether Beltran would be able to return next weekend for RSL’s last regular season game, but Petke described the injury as “pretty bad.”

“The match kind of got out of control a little early on, and there is a reason why it got out of control,” Petke said.

Beltran went down in the 24th minute, soon after one of RSL’s best goal-scoring opportunities. RSL winger Joao Plata narrowly missed on a breakaway set up by a pass from Luis Silva.

RSL regained possession after a Colorado clearance. Center back David Horst played a bouncing pass up the line to Beltran.

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Beltran turned, lifting his right leg to settle the ball, and Rapids forward Dominique Badji checked him on his blind side. Beltran’s leg extended as Badji turned his hip into him, and Beltran crumpled. He lay on the ground clutching his knee.

Referee Armando Villarreal issued Badji a yellow card for unsporting behavior.

Pace rushed onto the field to check on Beltran. After performing several tests on his right knee, Pace and Rapids doctor Wayne Gersoff helped him off the field.

When they reached the sideline, Movsisyan took over for Gersoff, supporting Beltran under his right arm.

On top of serving him well on defense, Beltran’s aggressive play on the outside has become an important part of RSL’s attack over the past few months.

“He does really well getting forward and getting good crosses in the box,” Horst said.

Still, RSL found a way to allow just two Rapids shots while missing two regular starters on the back line. In addition to Beltran’s injury, center back Marcelo Silva was suspended for a red card he received in RSL’s previous match, a 1-1 draw at L.A..

Horst started in place of Silva, and Demar Phillips made his first appearance since suffering a hamstring injury on July 19 to replace Beltran.

Colorado’s only goal of the match came in the third minute as Joshua Gatt broke through the RSL back line to give the Rapids an early lead. That allowed Colorado to put numbers behind the ball as RSL got off 30 shots but failed to score.

“I thought it was a beautiful game on our part,” Petke said. “I am not taking anything away from Colorado, they did what they did to get a result and they got it, my hat‘s off to them. It was ugly on one side; that’s the nature of it.”

Between RSL’s depth on the back line and Colorado’s defensive approach to the match, Real Salt Lake was able to keep the ball out of the back of the net for the rest of the match.

Midfielder Stefan Aigner took the Rapids’ only other shot of the game, which missed wide in the 57th minute.

RSL went to three in the back in the 78th minute. Then it moved to man-on-man for the final five minutes, playing a three-four-three.