Adam LaRoche. (Photo by John McDonnell/The Washington Post)

Adam LaRoche is back in Washington ahead of the Nationals, receiving treatment and resting his injury right quadriceps. LaRoche left the Nationals in Phoenix on Tuesday and returned to Washington ahead of the team, which will fly back after Wednesday’s game.

LaRoche is still in the midst of his resting period, which could last another four or five days, according to Nationals Manager Matt Williams. The Nationals still hope that LaRoche, the team’s best hitter, will return from the 15-day disabled list as soon as he is eligible on May 25.

“The results of the MRI as such that it’s not really a bad strain,” Williams said. “So it should heal fairly quickly. The key is not to push him too fast too early in the rehab and 15-day process to make sure he’s ready to go. He should be fine.”

By the end of the weekend, Williams said LaRoche could be beginning baseball activities again. LaRoche played through the quad strain for a week and a half before a setback in Oakland and finally landed on the disabled list backdated to May 10.

It is unclear if LaRoche will need a minor league rehab stint before he returns because it is still early. But it’s possible LaRoche could avoid one.

“He can still hit,” Williams said. “Hitting doesn’t bother him. It’s the running part. He can stay sharp and fresh. And even some monitored groundballs would probably be part of the protocol during the 15 days. It’s not like he has to sit out for a month and do nothing. It’s not like [Ryan Zimmermann] and can’t do anything baseball-wise. He can keep sharp. I don’t know if he’ll be needed.”

The Nationals have suffered through a rash of injuries to important starters in the lineup and the return of LaRoche after only 15 days would be a big boost to the lineup that already lacks Zimmerman and Bryce Harper. In his stead, the Nationals have used Tyler Moore and Kevin Frandsen at first base. But LaRoche’s .925 OPS and five home runs are hard to replace.

The Nationals are 20-19 six weeks into the season and have won three straight games only one in the past month, but a diminished lineup isn’t an excuse in Williams’ mind.

“We have professional baseball players on our team,” Williams said. “As evidenced two days ago, those guys can play well and come through and we can win a game. Losing games is frustrating at any time regardless of who is on the field. And you can’t say, ‘Boy, we don’t have our big guys so it’s okay.’ It’s never okay. And we don’t feel that way.

“We have to play well and do things right. We have to come through with guys on base, pitch well and defend well and all of those. There’s probably a little more emphasis on it now because you don’t have your starting nine as you laid it out in spring training but it is what it is and there’s nothing we can do about it. Those guys in the lineup have to step up and we have to play well. It’s a challenge certainly. We still have to play.”

>>> Nate McLouth is in Wednesday’s starting lineup against right-handed starter Brandon McCarthy. During batting practice before Monday’s game and during the game, McLouth tore the healing glue on the gash on right hand. McLouth suffered a deep cut in between his thumb and right index finger during a catch in which he slammed against the wall in left field at Nationals Park last week.

McLouth pinch hit during Tuesday’s game. He said he was fine to play on Wednesday as he received new healing glue and a covering on the gash.