SEATTLE -- Hisashi Iwakuma threw a solid five innings in his first Major League start on Monday, with only a three-run home run by Chris Davis marring a three-hit performance.

But with Kevin Millwood returning to the rotation this weekend and Erasmo Ramirez potentially coming back from the disabled list in time to start after the All-Star break, Iwakuma won't be in line for another spot start unless something goes wrong, it appears.

"We're OK now," manager Eric Wedge said Tuesday. "We don't have to worry about it until after the break, really. He'll be available for us this weekend [in the bullpen]. Let's see how Ramirez comes back. We've got time now. Between the off-day and the break, we don't have to make any decisions until afterward."

Millwood will start Friday in Oakland after being pushed back four days due to a sore groin. Ramirez is on the disabled list with a strained elbow, but is eligible to return by July 16. With the All-Star break, the Mariners won't need their fourth and fifth starters again until July 16 and 17 in Kansas City.

Iwakuma had been pitching in long relief for the Mariners up until Monday, but was always a starter in Japan. He's been improving steadily since Spring Training as he adjusts to the Major Leagues and gains strength from a shoulder injury that hampered him in 2011.

"My velocity is better than Spring Training, obviously, and my breaking balls are moving better," Iwakuma said through translator Daisuke Sekiba. "It feels better right now to pitch."

Carp could be moved to first after rehab

SEATTLE -- Mariners left fielder Mike Carp put on a pretty good show in early batting practice Tuesday and then met with manager Eric Wedge and general manager Jack Zduriencik to talk about his future as he comes back from a second stint on the disabled list with a sprained shoulder.

As a result, it appears the next step will be to convert Carp back into the first-base role he had much of his career coming up with the Mets and then with the Mariners when they acquired him before the 2009 season.

Wedge said Carp would go out on a Minor League injury rehab stint in the next few days, even though he's yet to start throwing. He'll be used as a designated hitter initially and then at first base when he can work that in.

Carp was one of the Mariners' breakthrough players last year when he hit .276 with 12 home runs and 46 RBIs in 79 games after spending most of the first half at Triple-A Tacoma. But he sprained his right shoulder diving for a ball in the season opener in Tokyo this April and hit just .157 in 32 games after trying to come back.

"I want him to be healthy, I want to see him hit and I want to be able to evaluate him and look at him and get him back here," Wedge said. "So right now, we're just going to focus on first base for him. We tried to do it the first time in the outfield, it didn't work. It affected his swing.

"Nothing has really changed outside of him getting stronger. But he was stronger the first time coming back, too, and he wore himself down. To get him back and keep him back, we're going to start him at first base at least for a while and go from there."

Mariners' 'pen emerging as one of game's best

SEATTLE -- The Mariners' bullpen has developed into a considerable strength this season, a fact driven home when the group set a club record for the lowest bullpen ERA for a month with their 1.88 mark in June.

The previous record was 1.97 in July of 2001. Mariners relievers went 8-2 with seven saves and just 20 earned runs allowed in 95 2/3 innings in the month. And they certainly haven't slowed down since, posting four hitless innings with just one walk in Monday's 6-3 win over the Orioles.

"Guys are stepping up in situations," said right-handed setup man Shawn Kelley. "It's a good group, pretty young overall and we all pull for each other and work hard and lock it in down there and pay attention to what's going on. And I think you're seeing that preparation on the field now. It's a fun group and it's showing out there."

The bullpen has solidified with the move of Tom Wilhelmsen to the closer's role. Wilhelmsen has not allowed a run in his last 19 2/3 innings and is 7-for-7 in save situations. Left-handers Charlie Furbush and Lucas Luetge have been excellent as well.

Steve Delabar, who pitched two scoreless innings and got the win on Monday in his first outing since returning from Triple-A Tacoma, said the group feeds off each other.

"Although I wasn't here the whole time, you pay attention to what's going on," Delabar said. "You just kind of want to follow suit and go along with what's going on. You do your work, you're just ready at all times. When the phone rings and they call your name, you get up and get loose and if they get you in, you get your job done.

"For us, there is no other way. It's 'I'm getting the job done' because you're backing up the guy in front of you and you just want to follow suit. If a guy leaves a couple runners on, you want to go in and shut it down for him because these are your boys."

Manager Eric Wedge has been impressed with the depth of the bullpen, which recently has added lefty veteran Oliver Perez and now Delabar back to the mix.

"They've been on quite a stretch here and we've had multiple guys down there really stepping up for us," Wedge said. "That's been really good to see."

Worth noting

• Center fielder Franklin Gutierrez is eligible to come off the seven-day concussion disabled list on Friday, but manager Eric Wedge didn't sound like that was going to happen after meeting with him on Monday.

"He's still a little off," Wedge said. "I think it would be a stretch to say he'd be back before the All-Star break. Having said that, he's having a total evaluation today and maybe he comes in feeling great, but I wouldn't count on it. He's getting better, but he's not where he needs to be quite yet."

• Rookie reliever Stephen Pryor, on the DL with a pulled groin muscle, threw a bullpen session and did some fielding drills to test his sore leg on Tuesday. He'll travel with the team to Oakland this weekend to continue his work, then likely will go out on a rehab stint after that, Wedge said.

• Michael Saunders was back in the lineup on Tuesday after missing four days with the stomach flu.

• First-round Draft pick Mike Zunino took batting practice with the Mariners after signing his contract on Tuesday. And after a slow start, the catcher from Florida ripped a series of deep drives into the seats in left field, including a couple impressive upper-deck shots.

"He looked good," said Wedge. "He hadn't hit in a couple weeks and the more he was in there, with the wood bat and all, the more comfortable he was. There's a lot to like there."