MINNEAPOLIS -- Justin Smoak remained sidelined for a sixth straight game on Friday as Seattle opened a series with the Twins, with Kendrys Morales again at first base.
Smoak hasn't started a game since feeling the oblique muscle in his right side tighten up on a checked swing last Saturday in Seattle. He did have one pinch-hit appearance Thursday in San Diego while batting right-handed, but he remains unable to fully swing left-handed, and thus wasn't in the lineup against right-hander Mike Pelfrey on Friday.
The Mariners don't face a lefty until Sunday's series finale against the Twins when Scott Diamond will be on the mound, so that's the likeliest time for him to return.
"I took batting practice today right-handed and it felt better than the other day, but I still haven't done very much left-handed," Smoak said. "So it's day by day with that and see how that goes. Right-handed, it felt a little better. But it's one of those things where I'm kind of scared to let it go right now. I've had it before, so I don't want to overdo it."
Smoak missed nearly a month with a strained oblique in 2009 while in Double-A ball in the Rangers organization, so he's admittedly being more cautious this time.
"It's just one of those things where it feels fine and I can do whatever I want to do," Smoak said. "But every once in a while swinging left-handed off the tee, I'll feel it a little bit. So I don't want to push it. I'd rather be out a week than a month. So we're just trying to take it day by day to see how it feels."
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.