"It was good," Smoak said of his brief rehab stint. "I got some at-bats in and got it tested as much as possible. The last two to three days have been great. I haven't really felt a thing, so hopefully I can stay right there."
The Mariners can use Smoak's return, as first baseman Kendrys Morales has been limited to designated-hitter duties in recent days by a sore back. Outfielder Michael Morse has been filling in at first base, but he's also been slowed the past two weeks by a strained quadriceps muscle in his right leg.
"It's important," manager Eric Wedge said of Smoak's return. "He's a fantastic first baseman and he was heading in the right direction offensively before he got hurt."
Smoak, 26, was hitting .240 with three home runs and eight RBIs in 46 games before he hurt the muscle in his right side on a checked swing on May 25. He made one appearance as a pinch hitter on May 29 before going on the 15-day disabled list.
Smoak's on-base percentage of .350 is the highest of any Mariners starter other than rookie second baseman Nick Franklin, who has put up a .382 mark in his first 20 games.
"I feel like I can come right back in and be productive," Smoak said. "That's the key. Try to drive some runs in and do what it takes to win some ballgames."
Liddi hit .059 (1-for-17) in eight games in limited duty while filling in mostly at first base since being called up from Tacoma on May 29.
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.