MINNEAPOLIS -- With center fielder Franklin Gutierrez back with the Mariners on Monday, Michael Saunders knows his role will change for the remainder of the season after manning that position most of the season's first 128 games. But Saunders is fine with playing wherever needed, once he gets himself healthy again after missing a third straight game with a sore groin muscle.

Saunders was sidelined again Monday after hurting the groin in a ninth-inning outfield collision with Eric Thames on Friday, but says he's close to returning.

"I went out and ran today and did some exercises in the gym," the 25-year-old outfielder said. "It's a lot stronger. At different movements, I'll still feel it a little, but it's already a lot better than even yesterday. So, I'm definitely making strides in the right direction and I'm confident I'll be back in this series."

Manager Eric Wedge said Saunders would definitely play one of the corner outfield positions when Gutierrez is in the lineup, which figures to be pretty much every day if he remains healthy after returning from a concussion.

"He'll play center when Guti doesn't, otherwise I'm comfortable with Michael in left or right, depending on who else is out there," Wedge said.

And that's fine with Saunders, who began the spring in competition for the left field job before moving to center when Gutierrez tore his pectoral muscle and missed several months and then shifted back over again when Gutierrez got hit in the head on June 28.

"I'm comfortable in either corner," said Saunders. "One of the beauties of playing center field, if you can play center, you can play the other ones. It's a different trajectory off the bat, obviously. But we legitimately can field three center fielders out there at one time."

Saunders said he's watched and learned from Gutierrez in the last few Spring Trainings and welcomes his return.

"What he can do for the club, not just defensively, but offensively, as well, he's a weapon and we're real glad to have him back," said Saunders. "He's going to do nothing but help this ballclub."

Mariners activate Gutierrez, option Wells to Minors

SEA@SD: Gutierrez makes a great diving snag in center

MINNEAPOLIS -- After two months on the disabled list following a concussion, center fielder Franklin Gutierrez was activated Monday by the Mariners and immediately inserted into the lineup for the opening game of a four-game series against the Twins at Target Field.

Outfielder Casper Wells was optioned to Triple-A Tacoma to make room on the 25-man roster.

"It's great to have him here and in the lineup and around his teammates again," said manager Eric Wedge. "He's worked hard and he wants to play. He's excited to be here. It felt good writing his name in the lineup today."

Gutierrez, 29, had played only 13 games this season after coming back from a partially torn pectoral muscle when he got hit in the head by a pickoff throw to first base on June 28. After dealing with recurring headaches, he finally was able to make a rehab stint with Tacoma and hit .333 with seven RBIs and two home runs in seven games.

He'll provide some center field options for Wedge, with Michael Saunders having missed three games now with a groin injury after colliding with right fielder Eric Thames in the ninth inning of Friday's 9-8 loss to the White Sox.

Gutierrez just wants to finish this season up strongly after the difficulties of the past five months.

"For me, it's very important to be healthy," he said. "Everybody knows what's been happening to me the last couple of years. I just want to keep that behind me. The team is doing good right now. They're playing good baseball. I just want to be part of it. I'm going to come in and try to help my team any way that I can, and that's the most important thing for me right now."

Gutierrez was a 2010 Gold Glove Award winner and is one of the premier defensive center fielders in the game when healthy, but has struggled to stay on the field the past two seasons. He played just 92 games while hitting .224 in 2011 after dealing with a digestive issue early in the year and then straining his oblique muscle in the final month.

A career .256 hitter in eight years in the Majors, Gutierrez was batting .267 with two home runs and nine RBIs in 45 at-bats this season when he was hit in the face by Boston's Franklin Morales while going back to first base.

Wedge had him hitting second in Monday's game, back in the same spot he'd elevated himself to when he got hurt a second time.

"There's no sense wasting any time with it," said Wedge. "He's a veteran guy. We had him up there before when we had him, albeit it briefly, and he did a nice job for us. I like him up there. Time is running short in regard to this season, so there's no sense wasting any time. He's a good player and he's ready to go."

Gutierrez said it was the second concussion of his career, the first coming about 10 years ago as a Minor Leaguer when he got hit in the head with a 98-mph fastball and missed about a month's playing time.

Wells, 27, has hit .226 with eight home runs and 29 RBIs in 74 games with the Mariners. He snapped an 0-for-16 slump with a two-run home run in the fifth inning of Sunday's 4-3 loss to the White Sox.

Wells had lost playing time recently with Trayvon Robinson getting most of the duty in left field and Eric Thames in right. He'll be with the Rainiers for their season-ending eight-game road trip starting in Las Vegas on Monday night, then be eligible to rejoin the Mariners after Tacoma's season ends on Sept. 3.

"He gets a chance to go down there for a week and get everyday at-bats," Wedge said. "Trayvon and Eric have both been playing pretty well. Casper's playing time had obviously diminished, so he was the odd man out. We'll get him back up here in September."

Millwood upset at himself, not weather

MINNEAPOLIS -- There was some question after Sunday's 4-3 loss to the White Sox as to whether the Mariners asked umpiring crew chief Jim Joyce to stop the game and try to dry out the surface in what turned out to be a six-minute delay just before pitcher Kevin Millwood surrendered the go-ahead two-run home run to White Sox catcher Tyler Flowers.

Millwood had yelled out loudly on the seventh-inning pitch before umpires called for the grounds crew to spread Diamond Dry on some growing puddles around the infield during the heavy downpour, which was coming with two outs and the Mariners leading, 3-2.

But Millwood said Monday he yelled in frustration at himself for walking Jordan Danks, wasn't having trouble with his footing and didn't ask for any grounds crew help.

"No, I was just ticked that I walked the guy. That's all," Millwood said. "I just wanted to throw him a strike, get him to hit a fly ball to left field and get out of there."

Instead, the umpires chose to delay the game at that point, but didn't call for the tarp. Instead, dry sand was spread around, the game resumed, and on his second pitch after the delay, Millwood gave up the home run.

Two batters later, the umpires stopped the game completely to have the tarp come out and the rains never let up enough to resume action.

"After that walk, I thought Joyce said they were going to tarp the field," Millwood said. "Instead, they put the kitty litter down. I didn't know what to do. I was a little lost."

The Mariners huddled on the mound in the downpour for several minutes. Millwood walked at one point to the dugout and then went back out and threw some warmup pitches before the game resumed.

"I still felt good," he said. "Everything felt like it was still working. I just made a bad pitch."

Manager Eric Wedge said the umpires made the best call they could, but didn't get accurate information from weather forecasters.

"They can only work with the information they're getting, whether it's from the local or national forecasters," said Wedge. "The fact of the matter is, it wasn't tracked very well -- not by the umpires, but by the forecasters -- and it worked against us.

"The umpire was trying to make a go of it with the information he had. I went out right away when he did stop it and I wasn't very happy about it. But he assured me that with the information he had, we were going to play again. We were definitely going to get this thing going again. You have to trust that, but then the story changed."

Worth noting

• First baseman Mike Carp, on the 15-day disabled list with a strained groin muscle, was scheduled to make his first rehab start on Monday at designated hitter for Triple-A Tacoma at Las Vegas.

• After losing three straight one-run decisions to the White Sox, the Mariners lead the American League and are third in the Majors in one-run losses at 23. The Mariners have played the most one-run games in the AL at 41, with an 18-23 record.

• Mariners top prospect Danny Hultzen was selected as the PERT Plus Minor League star of the year in a fan vote. Hultzen was selected as the Triple-A pitcher with the brightest future.