© 2013 MLB Advanced Media, L.P. All rights reserved.

6/10/2013 10:01 P.M. ET

With Morales back at first, Morse DH's opener

SEATTLE -- After spending Sunday at designated hitter to rest a sore back, Kendrys Morales returned to first base Monday as the Mariners opened a three-game set with the Astros.

"He says he feels good enough to get back in there," said manager Eric Wedge. "And that allows us to DH Michael Morse. We'll see how [Morse] is tonight, too. He was pretty sore yesterday."

Morales has been the Mariners biggest offensive threat, hitting .293 with eight home runs and a team-leading 35 RBIs in 239 at-bats as a needed middle-of-the-order presence.

"That's something we haven't had here the last couple years," Wedge said. "Now we have to do a better job of surrounding him. He's a switch-hitter with some power, a run producer. He's a great influence, as are the other veterans. But Kendrys just has a way about him with all the guys."

Morales has been the Mariners' best clutch hitter as well, with his eight game-winning RBIs tied for second in the American League.

Hitting flip tosses, Smoak nears rehab assignment

SEATTLE -- First baseman Justin Smoak took some left-handed swings Monday and said he's close to being ready to return to action, though the Mariners plan to send him out on a Minor League rehab assignment with Triple-A Tacoma before he rejoins the club.

The switch-hitting Smoak, out since May 30 with a strained oblique muscle in his right side, has been hitting off a tee for the past few days and took full swings on flip tosses Monday in the batting cage for the first time.

"Everything felt good," Smoak said. "I was finally able to let it go a little bit today. Right-handed has felt fine, it's just been left-handed that I've been worried about. It's more just my mind letting it go on that left side. Now we'll take batting practice tomorrow in the field and go from there."

The Mariners would like to get Smoak back and healthy as Michael Morse and Kendrys Morales have also been hampered by injuries the past week. Morse, battling a strained right quad, was at designated hitter again Monday against the Astros.

Manager Eric Wedge said if Smoak was healthy, Morse would likely be on the disabled list, himself. But the club's options are limited.

"With Smoak, it's more about hitting from the left-handed side," Wedge said. "We don't want to send him out until he's further along left-handed. Right-handed, I think we're in pretty good shape. It's just a matter of when he's able to let it rip."

Outfielder Franklin Gutierrez is also close to a rehab stint with Tacoma. He did running drills Monday and will start a second rehab program with the Rainiers soon as he continues recovering from a strained hamstring.

Shoppach starts again with catching depth thin

SEATTLE -- Kelly Shoppach was again in the lineup Monday for the Mariners' series opener against the Astros as Eric Wedge continued rolling primarily with the veteran catcher in his short-handed backstop situation.

Since Jesus Sucre injured his hand last Tuesday, Shoppach has caught 45 of the team's 52 innings, including all of Wednesday's 16-inning marathon, with rookie Brandon Bantz starting once and catching the first seven innings Saturday.

Shoppach, 33, has already caught 33 games and had 101 at-bats through this season's 64 games after averaging 199 at-bats over the past three years.

"Every game is a challenge," said Shoppach. "But physically, I've felt great. No more than normal dings and bumps a catcher would have at any time. I credit my strength and conditioning in the offseason. Even though, coming into each season, I know I'm not going to be an everyday guy, we train as if I'm going to be in case that comes up, then I'll be able to do it.

"A lot of guys mentally have the ability to catch every day, but if your body won't stay where your mind needs it to be, you won't be the player you should be. So we train the body just in case."

Shoppach enters Monday's opener hitting only .198, but knows that isn't the critical part of his game at the moment.

"The most important thing for me is to stay on point defensively," he said. "That's mainly where my value lies and why I'm able to continue to get jobs, I think. That's the one thing you can control, your effort and how you perform defensively. Your offense is going to have ups and downs, and you try to limit your bad stretches, but defensively, we're involved in every play. We're right there with the pitcher on every play. You have to stay strong."

Worth noting

• Brandon Maurer allowed just five hits and one run in six innings with two walks and six strikeouts, but took a loss in Tacoma's 7-1 defeat Sunday. Maurer is 0-1 with a 1.42 ERA in two starts since being optioned to Triple-A on May 29.

• Veteran right-handed reliever Josh Kinney, on the 60-day disabled list with a rib injury since Spring Training, has been sent on a Minor League rehab assignment with Tacoma.

Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.