The Mariners are about to learn whether their offseason efforts to build rotation depth can provide the protection envisioned in a season marked by their declaration to do "Whatever It Takes" to end a 15-year postseason drought.
Left-hander Drew Smyly will open the season on the disabled list after being diagnosed with a flexor strain in his elbow. The injury surfaced Tuesday when he experienced problems in a routine between-starts bullpen workout.
"We don’t think this is going to result in a surgical intervention," general manager Jerry Dipoto said, "but more rest and rehab. We do anticipate this not being a short-term thing.
"This is probably a six-to-eight week stretch that we’re going to be without Drew."
The Mariners replaced Smyly by recalling left-hander Ariel Miranda from Triple-A Tacoma.
"When we optioned Ariel to Tacoma," Dipoto said, "it was with the understanding that he was our sixth starter. We did not want to keep him in the big leagues and shorten his innings. We wanted to make sure he was stretched out."
This is Smyly’s fifth trip to the disabled list since 2012. He missed much of the 2015 season because of tendinitis in his shoulder but appeared fully recovered last season when he made a career-high 30 starts.
"Drew is now visiting with other doctors," Dipoto said. "He’s not in camp right now. He’s had health issues in the past that were not related to his elbow. This is something entirely new and different."
Smyly’s anticipated recovery period is just an estimate until the Mariners obtain the results of his second- and third-opinion examinations.
"What we’re looking at is a two-month window where we anticipate a rest-and-rehab," Dipoto said. "Whether that is baseball activity in six weeks and conceivably back on the mound in eight weeks remains to be seen."
Miranda, 28, made 10 starts last season after the Mariners acquired him from Baltimore in a July 31 trade for veteran lefty Wade Miley. Miranda was 5-2 with a 3.54 ERA overall in 11 appearances after the trade.
"Personally," Miranda said, "it was good news that the team kept me in mind when the need arose. Obviously, I’m happy about that."
The Mariners once appeared likely to shift Miranda to the bullpen after offseason trades netted Smyly and right-hander Yovani Gallardo, but club officials chose instead to keep Miranda stretched out as a starter as a hedge against an injury.
That decision now looks prescient.
Even so, Smyly’s injury represents a significant blow.
"I’d be lying to you if I told you there wasn’t a degree of disappointment," Dipoto said, "but we can’t focus on that. We have to focus on the positive.
Smyly, 27, appeared to be in fine form this spring, which included a strong start for the United States in its gold-medal run through the World Baseball Classic. He gave up one unearned run in 4 2/3 innings on March 15 against Venezuela.
For the Mariners, Smyly had two scoreless outings before getting roughed March 26 for five runs in four innings against Cincinnati in Goodyear. His troublesome bullpen outing came two days later.
"He was throwing great when he got to camp," Dipoto said. "He was throwing great when he left for and threw (in the WBC). We all watched it. Good, bad or indifferent, he just hasn’t been quite the same since he got back."
With Smyly, the Mariners were (and still are) betting on potential. He was just 7-12 last season for the Rays while serving up 32 home runs and compiling a career-worst 4.88 ERA.
But Dipoto and the Mariners saw a still-young lefty ready to blossom after four-plus years in the big leagues. They also saw a fly-ball pitcher who figured to benefit from their upgraded outfield defense and by pitching in Safeco Field.
"We gave up a package of players to get him," Dipoto said, "with the idea that this guy really fits our ballpark, our team — and he fits us for more than 2017. So we want to make sure that we’re doing the right thing for Drew."
The Mariners acquired Smyly from Tampa Bay in a Jan. 11 trade for three minor-league players: outfielder Mallex Smith, infielder Carlos Vargas and left-handed pitcher Ryan Yarbrough.
That move came after a deal earlier that day to get Smith from Atlanta with reliever Shae Simmons in a trade for minor-league pitchers Luiz Gohara and Thomas Burrows.
"My glass-half-full way of looking at this," Dipoto said, "is sometime around the start of June we’re anticipating acquiring Drew Smyly to rejoin our rotation and help us get over the hump."
Bob Dutton: @TNT_Mariners