Minnesota United is being cautious with top center back Ike Opara after he was involved in a scary head-to-head collision in the second half of the Loons’ 3-3 draw with New York City on Saturday.

Opara collided with Valentin Castellanos in the 82nd minute of Allianz Field’s opening game in St. Paul. After being subbed out, he needed seven stitches to stop the bleeding to his forehead. He didn’t participate in Tuesday’s training session in Blaine and his status is up in the air for Friday’s game at Toronto.

“It’s probably going to be a bit too soon for him this week,” United coach Adrian Heath said Tuesday. “We will give him every opportunity. May be a game-day decision; we’ll wait and see.”

The Loons (3-2-1) and Toronto FC (3-1-1) have a 7 p.m. start time at BMO Field. The potential absence of their best central defender is of particular concern because Toronto is tied for the second in MLS scoring with 14 goals this season.

The club has been closely monitoring Opara for concussion symptoms but he hadn’t shown any as of Tuesday afternoont. He worked out indoors, then watched the latter stages of the first team’s outdoor session.

“He got a bad bang, obviously, and he got a bad laceration and so his eye’s a bit puffy and everything,” Heath said. “As I said, it’s more day to day.”

Regarded as one of the best defenders in MLS, Opara has played 534 of 540 minutes in six games this season. If he can’t play, Brent Kallman would most likely receive the start.

FRIENDLY

United announced Tuesday a friendly with Aston Villa set for Wednesday, July 17. This exhibition against the Birmingham, England, club, which plays in the second division Championship, will fall between weekend MLS matches on July 13 and July 20.

The game will be the Loons’ second international friendly this season, with a previously scheduled match against Germany’s Hertha Berlin coming May 22.

TWO MORE TO MADISON

Forward Abu Danladi was able to benefit from a short stay with USL affiliate Forward Madison in its 2-0 win over the Wisconsin Badgers in an exhibition game Tuesday night in Madison. Danladi scored a goal off a header in 45 minutes of action in the first half, with Loons midfielder Hassani Dotson played the full 90.

Both Danladi and Dotson are expected to now travel back to Minnesota and be available to travel with the first team to Toronto on Thursday.

Danladi has one goal in 97 minutes in four games for the Loons. He scored in a 3-2 win at New York Red Bulls on April 6 and came off the bench to play 12 minutes against NYCFC on Saturday.

BRIEFLY

Midfielder Miguel Ibarra, who missed the Allianz Field opener with a hamstring injury, returned to training Tuesday, the Loons’ first outdoors in Blaine this season. … The Loons’s 14 goals are also part of the four-way tie for second-most scored in the league this season; Los Angeles FC is well ahead of the pack with 21. … Defender Chase Gasper (hamstring) did light running on the side Tuesday.