He missed Saturday's 1-0 Major League Soccer win over the visiting Columbus Crew with a rib injury and says he is feeling better, is back training, and hopes to play in Saturday's match against Chivas USA at the Home Depot Center in Carson, Calif.
Mwanga has yet to hit the score sheet this season, although on this team he's certainly not alone in that regard. Still, for a player who showed so much progress as the first overall pick in the 2010 MLS SuperDraft, Mwanga has seemingly taken a step back.
Part of that has been due to injuries, but he has not shown consistency. Mwanga can make one play that will take the fans' breath away and then disappear for 20 minutes during a game.
Yet his talent is undeniable, and so is his effort. It's the production that hasn't been there.
It's no surprise that Mwanga handled the acquisition of Herdling without a hint of controversy when asked if the situation put more pressure on him to perform - or more accurately, to get the chance to perform.
"I don't think it really puts pressure [on me]," Mwanga said Wednesday after practice at PPL Park in Chester. "To me [Herdling] is more like an attacking midfielder, which is great. We played a little together and he will be great for our team."
It's hard to say whether the Union would have pursued Herdling even if the offense was not struggling, but the guess here is that they would have. Team manager Peter Nowak seems enamored of the 27-year-old Herdling, whom he calls a great role model.
"He always wants to be around the ball and is very technical," Nowak said.
However, while the Union always are looking for a good citizen, they would much rather have somebody who can hit the back of the net.
Mwanga fits the "good citizen" role and has shown flashes of brilliance as a player.
He had seven goals and four assists during a rookie season in 2010 that started slowly, and had five goals and four assists last season.
This year in four games, including two starts, he has just two shots.
One theory is that Mwanga is almost too nice a person, both on and off the field, and that he defers too much to teammates.
He is someone who never makes waves, even when it appears there should be more playing time, but he also understands that it has to be earned.
It's easy to forget that Mwanga won't turn 21 until July. He seems older simply because he is one of only four players who have been here since the inaugural season in 2010.
So for now, he is working hard just to get back on the field and is saying all the right things. He says there is plenty of room for another offensive player, and the statistics surely back this point.
Yet the Union could become even more of a force if Mwanga is able to regain his health, get some playing time, and finally find his scoring touch.
Contact Marc Narducci at 856-779-3225, firstname.lastname@example.org or follow on Twitter @sjnard.