CLEARWATER, Fla. — D.C. United midfielder Yamil Asad will miss about three weeks with a groin injury, a timetable all but ruling him out of the remaining preseason matches and casting doubt on his availability for the MLS opener.

Asad, the probable starter at left wing, was injured in the first half of the first preseason match Tuesday against the Montreal Impact in Tampa. United has five friendlies left, culminating Feb. 22 ahead of the Feb. 29 regular season debut against the Colorado Rapids at Audi Field.

Asad, 25, is beginning his second tour with United after recording nine goals and eight assists while on loan from Argentina’s Velez Sarsfield in 2018.

After returning to Argentina last year, he played just 19 minutes — inactivity that left him more vulnerable to muscular injury this preseason. United had to strike a balance between moderately building up his physical condition and preparing him for competitive action.

United Coach Ben Olsen, however, does have ample options in midfield. Paul Arriola, Edison Flores, Ulises Segura and Emmanuel Boateng could play on the left side. With Arriola, Flores and Segura unavailable, Boateng is likely to start there Saturday against the New York Red Bulls in Bradenton, Fla.

Center back Donovan Pines is dealing with a minor muscular ailment and is questionable for Saturday.

>> Flores, United’s prized winter signing, returned to his native Peru on Thursday for his final visa interview. If all goes well, he will rejoin the squad by the middle of next week.

Since reporting to training camp two weeks ago, the visa situation has limited his involvement in workouts and formal activity.

>> Estonian forward Erik Sorga received his work visa this week and arrived in Washington on Thursday for a physical. He was scheduled to join the delegation in Clearwater on Friday.

Sorga, 20, is projected to back up starting striker Ola Kamara. Sorga’s contract is with United’s second-division team in Loudoun County, but he will gain MLS status when the collective bargaining agreement between MLS and the players’ association is settled and the salary cap is set.

Arriola and goalkeeper Bill Hamid will face defender Joseph Mora and Segura in a U.S.-Costa Rica friendly Saturday in Carson, Calif.

>> United officials are hoping to finalize a deal to acquire a French-based defender by next week. The player’s identity has not been revealed. He is a center back who is also capable of playing left back in either a three- or four-man back line, according to two people familiar with the talks who did not want to be identified because of sensitive negotiations.

United would pay a transfer fee of between $500,000 and $1 million, and it would sign the player to a contract using targeted allocation money — a deal worth at least $500,000 annually.

The team currently has only six natural defenders under contract: center backs Pines, Frédéric Brillant and Steven Birnbaum; left back Mora; and right backs Oniel Fisher and Chris Odoi-Atsem.

In the preseason opener, with Mora on assignment with the Costa Rican national team, Odoi-Atsem started at left back.

Center back Aaron Maund and left back Duke Lacroix have been on tryouts for two weeks. Right back Carter Manley, a former United under-23 player who this offseason was waived by Minnesota United, joined the group Friday.

>> MLS and the players’ association announced Thursday that they have agreed to extend the terms of the collective bargaining agreement to next Friday, a week after the current deal was to expire.

“The two groups have engaged in productive discussions and will continue to negotiate a new CBA,” they said in a joint statement.

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