ST. LOUIS -- Rookie shortstop Brad Miller was taken out of the Mariners' game against the Cardinals in the fifth inning Saturday because of a strained left hamstring, and he will likely be sidelined the next several games, according to manager Eric Wedge.

"It's mild, but I'm sure it's at least going to be a couple days," Wedge said after the Mariners beat the Cardinals, 4-1. "Tomorrow will give us a much better idea where we're at."

Miller, 23, took over a starting role for Seattle from Brendan Ryan when he was called up from Triple-A in late June and has hit .260 with six home runs and 31 RBIs in 69 games.

He was 1-for-2 in Saturday's game before apparently injuring the hamstring while running out a sacrifice bunt in the top of the fifth. Rookie Carlos Triunfel replaced him in the bottom of the fifth. It was Triunfel's first appearance since being recalled from Tacoma on Sept. 3.

Triunfel wound up contributing a sacrifice bunt and a sacrifice fly in two plate appearances, driving in the final insurance run in the ninth with a fly ball to right field.

Ryan had been backing up Miller at shortstop until he was traded to the Yankees on Tuesday.

Mariners pay price for challenging Cards' Molina

SEA@STL: Cards strike 'em out, throw 'em out in ninth

ST. LOUIS -- It's generally not wise to try to run on Cardinals catcher Yadier Molina, a five-time Gold Glove winner who gunned down two Mariners in the ninth inning Friday as St. Louis beat Seattle 2-1 in 10 innings.

Molina, 31, has the highest caught-stealing percentage of any active Major League catcher at 44.6 percent, and he nailed Endy Chavez and Dustin Ackley in short order as the Mariners tried to put Friday's game in motion with the score tied at 1.

It was the first time a Cardinals catcher had thrown out two runners in the same frame since 2001 when current manager Mike Matheny pulled the feat.

Why challenge Molina? Chavez was moving in a hit-and-run situation with Michael Saunders, who had twice failed to lay down a bunt earlier in the at-bat against closer Edward Mujica.

"We've got a 3-2 count there, so we're going to put Endy in motion hoping Saunders can make contact there," Wedge said. "It looked like a breaking ball up a little bit. He's got to put that ball in play, especially after not getting the bunt down. Still, you feel okay with Endy running. Molina did a nice job."

As for Ackley, after the Mariners outfielder had singled in the following at-bat?

"When you've got two outs and a runner on first base, you can't just sit back and wait," said Wedge. "You have to try to make something happen. Ackley was aggressive and I thought he had a pretty good jump. But that was one of the better throws we've seen this year. That second one was about as good as it gets from Yadi."

Matheny, a former catcher like Wedge, understood the Mariners' aggressive approach, even against Molina.

"The game situation really led to that," said Matheny. "You've got a 3-2 count, a guy that might be throwing something slower and he actually did and Yadi still made up for it. I'm sure that's the same that they're going to do with just about any catcher behind the plate."

Felix, Mariners optimistic about ace's return

SEA@KC: Felix fans six, holds Royals to three runs

ST. LOUIS -- Mariners ace Felix Hernandez will throw a bullpen session on Monday in Detroit, after which the club will determine if he'll return to the rotation as early as Wednesday against the Tigers.

Hernandez has been sidelined since Sept. 2 with a minor oblique strain in his left side. He threw in the outfield prior to Friday's game at Busch Stadium without problems and will now test his side while working off the mound after the team arrives in Detroit for its next series in a 10-game road trip.

"Felix was very optimistic yesterday about his day," manager Eric Wedge said prior to Saturday's game. "He's going to throw a bullpen Monday, so we feel he's going to be able to get back into it."

The club has set Joe Saunders to start Monday against the Tigers, followed by rookie Brandon Maurer on Tuesday. But the Wednesday and Thursday starters in the four-game series won't be announced until Hernandez's situation is clarified.

The Mariners currently are going with a six-man rotation, including Hernandez. So if he does throw Wednesday in Detroit, he'd likely have one more start after that on Tuesday, Sept. 24, against the Royals in Seattle.

Iwakuma among AL's top pitchers in stellar first season

SEA@STL: Iwakuma fires seven frames of three-hit ball

ST. LOUIS -- How good has Hisashi Iwakuma been this season, his first full year as a starter in the Majors?

After seven scoreless innings in Friday's no-decision against the Cardinals, Iwakuma now ranks second in the American League in WHIP (1.03), second in innings (203 2/3), fourth in ERA (2.87) and fifth in strikeouts-to-walk ratio (4.36). He is second in opponent's on-base percentage (.263), fifth in opponent's batting average (.225) and sixth in opponent's OPS (.646).

The Cardinals were impressed after facing the 32-year-old from Japan for the first time, managing just three hits and two walks in seven scoreless innings.

"He does a nice job of pounding the zone," Cardinals manager Mike Matheny said. "You can tell he's been around a while. He knows when to attack it, when to expand. He's speeding guys up and slowing them down to some pretty extreme measures. He's got enough movement that he can challenge guys early in the count. He did a nice job, kept us off balance."

Iwakuma set a career high in innings when he reached 203 2/3 following Friday's start, surpassing his high in Japan of 201 2/3, set in 2008.

Iwakuma will start two more games if the Mariners stay in their current six-man rotation and manager Eric Wedge said Saturday the plan is to keep him in the mix the rest of the way despite his high innings total.

"I feel pretty good right now," Iwakuma said after Friday's start through translator Antony Suzuki. "At times I've felt a little fatigued during the season, but right now I feel better."

Iwakuma has had four straight no-decisions, but he's 2-0 with a 2.27 ERA over his last six starts to put him at 12-6 with a 2.87 ERA in 31 games.

Worth noting

• Third baseman Kyle Seager became the seventh player in Mariners history on Friday to start 100 consecutive games at the same position and first since shortstop Alex Rodriguez played 145 games in a row at shortstop in 1998, and Ken Griffey Jr. went 114 straight in center field the same year.

• The Mariners set a club record with their 13th extra-inning loss on Friday. They are 6-13 in extra innings and are two games shy of the record 21 bonus-panel games set in 1982.

Since July 1, 2012, Seattle has gone 6-21 in extra-inning games.