Wilson, an All-Star with the Bucs in 2004, had a sore left hamstring when he arrived in Seattle, and he missed 10 games after aggravating the injury. More recently, he suffered a bruised right heel on Tuesday, when he stepped awkwardly on the first-base bag.
He had an MRI exam on Friday and there was no structural damage detected.
"He's not going to travel [to Tampa and Toronto] with us," manager Don Wakamatsu said. "He'll stay here and continue to get some treatment. We don't know if he'll be able to play the rest of the year. We're hoping."
Wilson, who batted .267 with four home runs and 31 RBIs in 75 games with the Pirates, is batting .224 with one home run and eight RBIs in 31 games with the Mariners.
It has been a frustrating six weeks for Wilson, who welcomed the chance to play for a team with a winning record -- something he was unable to do during his eight-plus seasons with Pittsburgh.
Wakamatsu said the Mariners got only a glimpse of Wilson's ability.
"You look beyond the numbers sometimes and at the athletic ability, and how he understands the game and how he plays the game," Wakamatsu said. "He plays shortstop extremely well. Offensively, it's always tough switching from one league to the other. But he's a baseball player. I like what I've seen."
Wakamatsu said he recalled Sean Casey getting traded from the Tigers to the Reds at the July 31 non-waiver Trade Deadline, and Casey ended up hitting about .150.
"It's always tough going from one league to the other, but [Wilson] is a guy who's proven he can make adjustments, and there's no reason he can't," Wakamatsu said.
Wilson is in the final guaranteed year of his three-year $20.2 million contract, which includes an $8.4 million option next season, along with a $600,000 buyout. Seattle is paying just $250,000 of his '09 salary and must decide whether to pick up the option or exercise the buyout and try to work out another contract with Wilson.
Jim Street is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.