Lineup change and more on Britton rehab (O's down 3-2)

Third baseman Danny Valencia has been scratched from tonight's lineup. Jace Peterson is playing third base and Joey Rickard goes to left field and bats seventh in Valencia's slot.

Bryce Harper homered off Dylan Bundy in the top of the first inning to give the Nationals a quick 1-0 lead.

Zach Britton didn't know today whether he'd start or work a later inning in the first game of his rehab assignment. He felt confident only in his travel itinerary.

Britton was headed to Triple-A Norfolk until an unfavorable weather forecast left open the possibility that he'd pitch Wednesday for Single-A Frederick in Wilmington, Del.

All that really matters is his surgically repaired right Achilles tendon isn't prohibiting him from getting back on a mound in a competitive environment. That he's still projecting an early June debut with the Orioles.

Britton was in good spirits again today, teasing rookie pitcher Tanner Scott about needing a bigger travel bag to cart his equipment back to Norfolk. Scott insisted that it was only a couple of gloves.

The original plan called for Britton to keep pitching for the Tides, twice in their home ballpark and again next week in Columbus, though he wouldn't spend every day with them. But the pending rain had the Orioles ready to call an audible.

Britton said he'd return to Camden Yards before the next road trip to meet with manager Buck Showalter and pitching coach Roger McDowell.

"Before they go on the road we'll have the rest of the outings mapped out," he said.

Britton could pitch in back-to-back games and maybe work an inning and come back out to face another hitter.

"It's kind of at my discretion," he said. "Obviously, they don't want me to do it every time out."

They'd like for him to pitch at Harbor Park, but no one has found a method for controlling the weather.

"It's kind of iffy," Showalter said. "Instead of driving to Norfolk, which he was going to do tonight, and then have a weather issue and have to drive to Wilmington, we're thinking he's going to go to Wilmington today. It's only an hour-plus. Of the four affiliates, that's the best weather right now, but we know how it changes.

"He's not going to start and he's not going to pitch the ninth inning. He'll start an inning at some point. And he won't come in relief during an inning."

Britton's simulated game Saturday morning at Tropicana Field confirmed that he was ready for his assignment.

"If you didn't know the history and what all still needed to be done, you'd think that he could have pitched in the big leagues that night," Showalter said.

"The first guy had a broken-bat single into center field and he kind of got a little look on his face like, 'Mmm this, let's go.' I think when the competitive juices get going even more so ... Zach's been a model rehab guy, knock on wood. I'm not saying he's ahead or behind, but most of these things don't get as far as he's gotten without some little semi-setback, so it's been fun to watch. Hope he gets back soon.

"It makes everybody down there, it kind of settles things. We've gone quite a while here where the phone rang and really nobody had to answer it. They knew the situation and they knew with the rest, and we were able to spread the load around, which has been a challenge.

"Zach makes us better, but he makes people around him better. Very much like Darren (O'Day). I think it affects the whole atmosphere of a club when you have a lot of people trying to pick up the slack. It can be a challenge."

O'Day is progressing slowly from his hyperextended right elbow. He wasn't "a thrower" today, according to Showalter.

"We thought it would be best to wait another day until he gets that last part of discomfort out there," Showalter said. "Hopefully, we'll get him and Zach back before too long."

No sign of Trey Mancini in tonight's lineup. He's batting .198/.281/.327 in May, going 1-for-17 in his last four games and 6-for-53 in his last 13.

"Going to give Trey a day off. Nothing's really wrong with him. Just trying to give him a day away," Showalter said.

We've moved past Memorial Day and anticipation grows over potential changes to the Orioles roster. However, Showalter never shifts his focus from the current roster. He gets asked about trades every year and pretty much offers a stock answer.

If there's any buzz, he hasn't heard it.

"I'm not listening for it," he said. "I know they're all tied up in the draft meetings. That's really the focus now. They're gathering and getting ready for that very important draft. We've got three picks inside of 100. Got some young guys coming down below. It's real exciting to watch. But if someone thinks I need to know about something, they'll let me know.

"Trying to stay focused on getting better here. It's not something I ask, either. I know where my plate is."

I wrote earlier that Double-A Bowie outfielder Cedric Mullins was named Eastern League Player of the Week after batting .560. His average has risen to .313 with a .361 on-base percentage. The switch-hitter is batting .300 against left-handers after posting a .208 average last year.

"That's been a real tribute to him and the guys working with him down there. That's nice to see," Showalter said.

Minor league hitting coordinator Jeff Manto arranged for Mullins to bat on the back fields against former major league left-handed starters Scott McGregor and Wilson Alvarez, the pitching rehabilitation coordinator and Rookie-level Gulf Coast League pitching coach, respectively. McGregor and Alvarez passed along their observations to Mullins.

"They both ended up saying the exact same thing, that, 'If I was pitching to you, this is what I would do to you and where you're susceptible.' And it really seemed to hit a chord with Cedric, like, 'That's exactly what they do when I'm having trouble," Showalter said.

"It's pretty imaginative and you're lucky to have two guys like Scott and Wilson who had good major league careers to say that to somebody. You're reading swings all the time as a pitcher and both of those guys read him a lot.

"Cedric's doing well. He kind of heated up with the weather. It's tough sledding with a lot of those guys with the weather being so bad."

Mullins could be headed to Norfolk shortly, but again, Showalter isn't comfortable with talking about guys below the 25 on his roster. Whether it's trades or promotions.

"I really don't think it behooves necessarily for guys in our clubhouse to hear me talking about all these guys and trades and moves and what have you," Showalter said. "I'm hoping we can put together a really good 10 days and start this thing in the other direction."

Update: Manny Machado homered off Jeremy Hellickson in the bottom of the first to tie the score 1-1.

Update II: Wilmer Difo had an RBI single with two outs in the second inning and Mark Reynolds led off the fourth with a home run to give the Nationals a 3-1 lead.

Update III: Adam Jones' two-out double in the fifth inning scored Chance Sisco and reduced the lead to 3-2. Peterson was thrown out at the plate.