Franklin MoralesThe Red Sox used two left-handed relievers not named Craig Breslow on Saturday. The results were mixed.

Matt Thornton and Franklin Morales both took the mound in the Red Sox’ 6-5 loss to the Orioles. Thornton’s night went much smoother, although Morales faced a more difficult situation. Right now, there’s a chance that only one of the two southpaws will make the Red Sox’ ALDS roster. If that is indeed the case, Saturday only muddied the waters.

Thornton was the first lefty summoned from the Red Sox’ bullpen Saturday. He pitched a 1-2-3 sixth inning with Boston trailing 4-3. Thornton took care of Steve Pearce, Jason Pridie and Brian Roberts in order, with Pridie striking out looking on a nice fastball down in the zone.

Morales was called upon in the eighth inning with the Red Sox clinging to a 5-4 lead, and he failed to escape a jam that the Orioles built against Junichi Tazawa. Matt Wieters and Danny Valencia hit back-to-back singles to open up the eighth inning against Tazawa, and Morales entered to face the left-handed-hitting Nick Markakis. Morales struck out Markakis — after Markakis missed a home run by a few feet down the left field line — but failed to put away the next hitter. Pearce ripped a two-run double into the left field corner that gave the O’s a 6-5 lead that they wouldn’t relinquish.

The Red Sox’ bullpen implosion further highlights the club’s one glaring weakness heading into the playoffs. Koji Uehara has been dominant as Boston’s closer and Craig Breslow has been very reliable as well, but there are questions beyond those two hurlers. Tazawa and Brandon Workman (who successfully played damage control after Pearce’s two-run double) are the other locks for the Red Sox’ playoff roster despite their occasional moments of inconsistency, and the rest of unit will be rounded out by some combination of Thornton, Morales, Ryan Dempster and Felix Doubront.

John Farrell indicated in the past that the Red Sox were leaning toward carrying 11 pitchers — meaning that Thornton, Morales, Dempster and Doubront would be vying for three spots — although there’s certainly a chance that Boston could alter its game plan and go with 10 pitchers while carrying both Quintin Berry and Jackie Bradley Jr. In any event, Morales was, in all likelihood, a ground ball away from locking up a playoff roster spot Saturday. If he followed up his strikeout of Markakis with a successful escape, the Red Sox likely would have viewed that as evidence that he’s ready to tackle more high-leverage situations. Instead, he still only has one foot in the door.

Given the progress that Morales has shown over the last month, he’s probably a better option than Thornton at this point. Morales entered Saturday’s contest with a 1.93 ERA in September, his velocity is back to sitting at around 94-95 mph and he still has swing-and-miss potential despite some momentary lapses in control. Even after Morales was victimized by Pearce’s game-winning double Saturday, Farrell was quick to point out his overall stuff.

“He was dominant [against Markakis]. He was powerful. He punches him out on a good fastball. And then after a couple of foul balls by Pearce, the curveball stayed in the middle of the plate for the two-run double,” Farrell said. “But I thought Franklin was not only powerful, but consistent with the way he’s been the last seven to nine times to the mound for us. Unfortunately, we didn’t finish off a couple of hitters when we got ahead in a 1-2 count.”

Farrell clearly sees something in Morales, so perhaps the decision on whether to keep him around in October won’t really be all that difficult. Morales definitely missed out on a golden opportunity to end any debate, though, and Thornton stands to be the beneficiary if Boston ultimately decides not to carry Morales on its playoff roster.

Still, no matter which pitchers round out the bullpen, it’s hard to be overly confident in anyone not named Uehara or Breslow right now. That’s a scary thought for the Red Sox.

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