Servais said Martin's injury shouldn't keep him out long, but the club didn't want to rush him back and risk prolonging the problem.
"It was a situation where was it going to be seven days or 10 days?" Servais said. "With a speed player with a hamstring injury like that, it's delicate and you maybe need to be a little more cautious with it. If you play first base or third base or DH or something, it'd be a little different. But speed is such a big part of his game and how he plays and he's never had a leg injury before, so we just thought it would be best to be cautious with this. We have a lot of season ahead of us."
Martin had a .262/.339/.483 line over his first 44 games and already has hit a career-high nine home runs. The 28-year-old was acquired from Texas over the offseason to bolster Seattle's defense, but has hit .353 with 14 runs, five homers and a .423 on-base percentage over his past 20 games.
Romero was batting.358 with seven homers and 34 RBIs in 39 games for Tacoma. He appeared in the Majors with Seattle in both 2014 and 2015, batting .192 with four homers and 14 RBIs in 85 games.
Martin felt a twinge in the hamstring when he slid into second on a stolen base in the fourth inning of Wednesday's 13-3 win over the A's and was taken out after noticeably limping when he was caught in a rundown between third and home.
Martin said his leg felt much improved Friday before he headed in to meet with the team physician, but the Mariners will play it safe rather than push an injury that often can linger.
While Safeco Field and Petco Park, where the Mariners open their next road trip on Wednesday, both have large outfields, Servais said that won't impact who he decides to play in Martin's stead.
"They're all big when Leonys isn't out there. That's the way I look at it," Servais said. "He's such a premier defender that anybody you put out there that we have in our organization that could help, it's a step down. That's just the way it is. But you're hoping to get by in the short term and it doesn't get too exposed."
As for the batting order? Martin has been an energizer since Servais put him first last Sunday and dropped Aoki to the No. 9 spot. In the ensuing four games, Martin hit .533 (8-for-15) with a walk, a home run and three runs.
"That does affect us as well," Servais said. "But Nori has swung the bat excellent the last couple games. I think he's hit eight balls on the screws his last eight at-bats. Nori will slide back in there and we'll get it rolling with him again."
Martin said he's never had any hamstring issues before and his only disabled list stint during four seasons with Texas came last year when he fractured the hamate bone in his right hand on Aug. 13 after being optioned to Triple-A Round Rock at the end of a frustrating season with the Rangers.
"It's going to feel a little weird to be on the bench and see everybody out there fighting, but it is what it is," he said.
Martin becomes the second Mariners position player to go on the DL in the past week. Shortstop Ketel Marte sprained his left thumb last Saturday, but is expected to return when his DL stint ends on June 6.
Martin's DL stint is retroactive to Thursday, so he's eligible to return on June 10.