Bliss (torn biceps) to undergo surgery, miss 4-5 months

SEATTLE -- The hits kept coming for the Mariners on Thursday, as they will now be without Ryan Bliss for at least the next four to five months after the starting second baseman suffered a left biceps tear on a swing during Tuesday’s extra-innings loss to the Astros.

The club announced during Thursday's off-day that surgery is needed, after the severity of the injury was confirmed by an MRI. The procedure will take place Friday at the University of Washington Medical Center and be performed by Mariners’ orthopedic physician Dr. Albert Gee.

As part of Bliss being sidelined, Seattle made a series of roster moves leading into its series finale against Houston on Wednesday:

• Bliss (left biceps tear) placed on 10-day injured list
• INF Leo Rivas recalled from Triple-A Tacoma
• RHP Casey Lawrence selected from Tacoma
• RHP Jesse Hahn designated for assignment

Bliss suffered the injury when swinging through a curveball from Astros starter Framber Valdez in the second inning, an at-bat in which he eventually struck out. He exhibited some pain after the hack, then did a few tests immediately after but felt fine to remain in the game, going on to rip a 387-foot double off the left-field wall in the fifth.

Bliss also made a key defensive play in the 10th that kept the game alive, corralling a chopper from Jose Altuve while leaping to his right. Had the ball gone through, Astros speedster Chas McCormick almost certainly would’ve scored from second to break a 1-1 tie.

“I felt fine after that,” Bliss said, “and was like, 'I can still play.’ I made up all my defensive plays. But by that last inning, it was feeling a little tight, but I felt like I could still rock.”

Bliss, who won the second-base job in Spring Training, had started each of Seattle’s first 11 games at the position and was off to a 7-for-35 start at the plate with one homer, one double, three RBIs, 11 strikeouts and four walks, for a slash line of .200/.282/.314.

But it was the defensive strides Bliss made that were far more encouraging, especially given that his glove was an area of his game that he struggled with in his debut season last year. In a very small sample size, Bliss ranked in the 97th percentile in outs above average and the 95th percentile in fielding run value, both of which are tracked by Statcast.

“My only concern with him is sometimes he tries to be too quick,” Mariners infield coach Perry Hill said. “He has enough quick-twitch in his body to begin with; he doesn't need to be any quicker. But he's slowed down. The last couple of weeks of Spring Training and leading into the [regular season], he's really slowed down.”

In Bliss’ stead, at least on Wednesday, when the Mariners were facing a right-handed starter, lefty-hitting Miles Mastrobuoni started at second base. Rivas, an above-average defender who can play all three infield positions and switch-hits, will be in the mix too.

So will Dylan Moore, though he’s seen an enhanced role at third base while Jorge Polanco has been limited with a side injury. Polanco, who was the Mariners’ primary second baseman last year but transitioned to the hot corner, has been Seattle’s designated hitter for each of his past three starts.

“We'll continue to look at different options and see how we go forward from here,” Mariners manager Dan Wilson said. “Ryan played such a good defense there and really made the most of his opportunity when he had it. And now we're going to have to make our adjustment.”

Beyond Bliss, the Mariners have been battered by injuries in the early season.

On Tuesday, the club learned that right fielder and leadoff man Victor Robles will be out for at least 12 weeks with a fracture in his left shoulder following a catch into the netting on Sunday in San Francisco. All-Star starting pitcher George Kirby is still probably a month away as he continues to recover from right shoulder inflammation. And the status of Polanco, who also had offseason knee surgery but has been their best hitter so far, has been day to day.