SEATTLE — There was no reason to wait. If Michael Saunders was healthy enough to be activated off the 15-day disabled list, then he was going to be back in the starting line-up immediately.

As expected, the Mariners activated Saunders off the disabled list and sent optioned outfielder Carlos Peguero to Class AAA Tacoma to make room on the 25-man roster.

Mariners manager Eric Wedge penciled in Saunders into center field and in the leadoff spot on Monday night.

“He’s worked hard to get back and I’m glad to have him back,” Wedge said. “I’m excited to watch him play.”

Saunders rewarded Wedge by homering in his first at-bat of Monday’s game against the Baltimore Orioles. It was the first leadoff homer of Saunders’ career.

Saunders played three games with Tacoma in Las Vegas over the weekend on a rehab assignment. He went 2-for-11 with a double, a triple and two RBI.

“It felt good to get back out there,” Saunders said before the game. “Unfortunately, it was 97 degrees and I’m still feeling the effects of it. I seem to be sweating for no reason right now.”

But Saunders isn’t feeling the effects of the sprained acromioclavicular joint in his right shoulder he sustained on April 11th when he slammed into the wall making a first-inning catch against the Texas Rangers.

“I feel like I’m ready to come back,” Saunders said. “I passed every test I needed to.”

One of those tests was taking a good hard swing in a game situation without worrying about his shoulder. He did that on numerous occasions in Las Vegas.

“You get out there and your competitive nature takes over,” he said. “You’re not so tense. I learned in 2008 when I had my surgery (shoulder) that the last 5-10 percent is mental and just trusting that you’re healthy and ready to do it. Once I was at the plate, I took hard swings and it felt good to let it go.”

Saunders never had to make a hard throw in Las Vegas, and admitted his arm isn’t 100 percent when it comes to throwing. But it’s capable.

“I’m able to do my job out there,” he said. “I was able to play catch up to 140 feet on consecutive days.”

And that’s all he needs to be successful.

“My main goal is to be able to hit the cutoff man,” he said. “Basically, if you hit your first cutoff man, you are going to get more outs normally than you would if you overthrow and try to get them out at the base.”

How much can Wedge play Saunders coming off the injury?

“I told him lets just take it day by day,” Wedge said. “My plan is to have him play every day.”

Saunders will continue to do the shoulder exercises he did during his time on the disabled list to keep the joint healthy and the muscles around it strong.

I’m going to continue to stay on my program every day and that will be for the rest of the year,” he said. “Even after I feel nothing in my shoulder and I feel 100 percent, I’m going to make sure and stay on top of it. It’s something I have to do every day, but it’s a small price to pay to play every day.”

Also don’t expect him to be shy around the wall.

“If I can catch the ball then I’m going to try and catch it,” he said. “There is no point in playing scared, I’m out there to play hard. And that’s the way I’ve always played.

Short hops

Mariners minor league catching coordinator John Stearns filled in as the third base coach. Third base coach Jeff Datz was unavailable because of a prior medical appointment on Monday. On Saturday, Datz informed Wedge and the team he had been diagnosed with cancer. Stearns will stay with the team the next few days and fill in for Datz on the upcoming road trip. … The Mariners have Hisashi Iwakuma slated to start on Sunday in Toronto. That would give him two extra days rest to heal the blood blister on the middle finger of his pitching hand. … On the injury front, Wedge said “there is nothing to report” when it comes to Franklin Gutierrez’s strained hamstring. Reliever Josh Kinney (back) is throwing in Arizona and is moving closer to heading out on a rehab assignment. Starting pitcher Erasmo Ramirez (triceps) has also started throwing but is further away from returning.