Union’s Jamiro Monteiro finally back on field amid recovery from sprained ankle

Injured Union midfielder Jamiro Monteiro played in a 50-minute intra-squad scrimmage Wednesday, and manager Jim Curtin sounded cautiously optimistic that one of his team’s key players might play Sunday against Wayne Rooney and D.C. United (7:30 p.m., Fox Sports 1 and Fox Deportes).

“We’ll obviously have to see how his body responds, but overall, great to have him back in the group,” Curtin said. “He showed some rust, but he looked very good.”

Monteiro has missed four games with a sprained ankle, and the Union have missed his tenacity. The 25-year-old is the team leader in tackles per game (3.7) and ranks third in passes blocked (1.0). He also contributes a lot to the attack, ranking third in chances created per game (1.3) and pass-completion percentage (87.3, counting players with consequential playing time).

Brenden Aaronson, who has filled in for Monteiro on the left side of the four-man diamond, is more of an attacker than a defender. Aaronson has played 18 of the 22 games in his rookie season, racking up more than 1,300 minutes. The Medford native also got 45 minutes in Tuesday’s Homegrown Game showcase in Orlando, the prelude to Wednesday’s All-Star Game.

Curtin hinted that Aaronson might not be suited for a road game against a team hot on the Union’s heels in the standings.

“I think at this time of the year, it’s time for the experienced guys, the veterans, to step up, and I know they will,” Curtin said. “When we talk about shoring things up defensively, Brenden isn’t going to be the solution or problem in that regard. He’s an 18-year-old kid that’s out there pushing for minutes every day and doing a great job for us. ... When we talk about stability, that has to come more from our veterans and our leaders.”

Those veterans include right back Ray Gaddis, who Curtin defended after two poor performances in the last three games. Olivier Mbaizo is back from a torn meniscus and will play for Bethlehem Steel this week, but Gaddis probably will not be unseated soon.

“That’s an example of trying to find one guy to blame, and I think it’s unfair,” Curtin said about Gaddis’ form. “What he does every day in training, he stays healthy, he works his tail off in every practice. Did he have his best game? Absolutely not. But he knows that."