Tillman scratched from Wednesday start with sore shoulder (updated)

Chris Tillman's next start is being pushed back to Saturday night against the Astros due to some discomfort in his right shoulder. Dylan Bundy will pitch Wednesday night in the series finale against the Red Sox.

Manager Buck Showalter made the announcement following tonight's 5-3 loss to the Red Sox before 26,014 at Camden Yards.

"Bundy's going to start tomorrow. Going to bump Tillman back to Saturday, hopefully," Showalter said.

"I let the Red Sox know before the game. We talked about it after batting practice. One of the many things we look at during batting practice. A little shoulder discomfort. Just didn't like the description, talking to Richie (Bancells) and Tilly and Dom (Chiti) and Wally (Dave Wallace) on the phone. Stay on the safe side with the off day and keep everybody else in turn.

"(Yovani) Gallardo was working with an extra day. Other guys will be on turn and push Chris back to Saturday."

The discomfort wasn't an issue in Tillman's last start, when he held the Athletics to two runs in seven innings on Aug. 11 and improved to 15-4 with a 3.46 ERA in 25 starts.

"I saw it on the report a day or so ago," Showalter said. "Richie and I were talking about it on the plane a little bit and tonight, wanted to see how he felt today. It's better. He's getting there. We have the luxury of giving him the extra time and we're going to do it.

"A lot of things most starting pitchers go through, especially in August. But that's why I had pushed everybody back a day, give everybody some time. I want to wait and see how Yovani feels tomorrow. He took a pretty good blow off his forearm and he's got a knot there. It's one of those things you don't really feel for a long time, 20 minutes or so. And then they made a pitching change and all that other stuff and I didn't want to run him back out there. It's going to do nothing but get worse."

Tillman faced the Red Sox on June 14 and allowed one run and five hits over seven innings in a 3-2 win. He's 10-3 with a 2.74 ERA in 19 career starts, but he won't get another shot at them in this series.

Bundy has made four career relief appearances against the Red Sox, including his major league debut in 2012, and has allowed two runs and 10 hits in six innings.

Update: The Orioles fell into a second-place tie with the Red Sox after the Blue Jays defeated the Yankees.

Mookie Betts homered twice tonight and drove in all five Boston runs. He's hit seven homers at Camden Yards, most by any player in a single season, according to ESPN Stats & Info.

"I'm sure there are some numbers to dictate that it's more us, but he's been having that type of year against most everybody," Showalter said. "He's a really good player having a big year."

Gallardo served up a three-run homer to Betts in the fifth inning to break scoreless tie. The Orioles scored three runs in the seventh on Matt Wieters' two-run single and Adam Jones' bases-loaded walk, but Betts hit a two-run homer off Brad Brach in the eighth.

"Yovani pitched pretty well," Showalter said. "He made one mistake and Brad made one mistake and we paid for it. But he's a good player. We shouldn't feel like he's picking on us, but I know it seems like it.

"I just think (Gallardo) has been healthy since the break and feels confident with all his pitches. Yovani's going to go out there more times than not and give you a chance to win. It's a guy we wanted to acquire and he's a very competitive guy."

The Orioles were being no-hit by Eduardo Rodriguez until he exited in the fifth with tightness in his left hamstring. Matt Barnes finally gave up a hit in the seventh on Steve Pearce's infield single.

Gallardo took a comebacker from Dustin Pedroia off his right forearm in the top of the fifth and didn't come back out for the sixth.

"We weren't doing much offensively against either of their first two guys," Showalter said. "They've got a lot of good hitters and it's tough to hold them down."

Showalter didn't let Gallardo decide whether to return in the sixth.

"I don't like putting players in that position," Showalter said. "You know what the good ones are going to say, 99 percent of them. He had a good sequence, threw some of his best fastballs to (David) Oritz there. It just seems like every time we've made any type of mistake over the plate with Betts he's hurt us. Like he did Brad.

"It's like going out and asking a pitcher do you want to walk this guy or go after him? That's not his job. You don't ever put him in that situation. He tells me he's good to go and I trust him. He pitched well tonight. Just a small margin for error. We didn't hit many balls hard. But we had some opportunities there."

Opponents are 13-for-48 (.271) with six earned runs in 12 innings against Brach in the second half after going 26-for-168 (.155) with five earned runs in 49 1/3 innings the first half.

"He had a real good outing last time," Showalter said. "Won a game, right back out there. He's had some good outings. Those are good hitters and he's a good pitcher. More times than not, he wins the battle.

"He's going through a little period where every little mistake seems to get magnified. It's a real testament to him to come back after that and pitch to the next three hitters the way he did. That's why Brad is having such a great year, because of what he does after that happened. Most people would woe is me and make you bring somebody else in."

I asked Showalter about the lineup changes, with Pearce going to first base, Chris Davis to right field and Mark Trumbo to the role of designated hitter.

"I wanted to talk to some people, look at some things," he replied. "Chris and I talked about it about a week ago on that trip. It's kind of a day off. I don't mean it like he was just standing out there, but wanted to get him in right field. Wanted to get Trumbo off the field and wanted to make sure Steve was good enough physically to play first base. We couldn't do any of those things until we got through batting practice.

"Steve was good with first and Chris liked the idea of playing right and I know Trumb appreciated getting off his legs for a day. Had to wait to cross the t's and dot the i's. Plus, wanted to make sure we had something to talk about."