John LackeySometimes, sports just aren’t fair.

John Lackey, who missed all of the 2012 season after undergoing Tommy John surgery, worked relentlessly to get back to where he was entering Saturday’s game in Toronto. The right-hander’s elbow injury was finally in the rear view mirror, and he was ready to tackle 2013 with enthusiasm and confidence.

A two-pitch sequence changed everything.

Lackey had just struck out Emilio Bonifacio to lead off the fifth inning, and he seemed very much in control. The strikeout against Bonifacio was Lackey’s eighth of the game — a mark he had only reached three times since joining the Red Sox — and his only mistake was a relatively flat offspeed offering that J.P. Arencibia drove over the center-field wall in the fourth inning.

Jose Reyes, who has been a thorn in Boston’s side during the first two games of the series, stepped up, and eventually fouled off a 2-2 pitch. It seemed relatively harmless at the time, but something clearly wasn’t right with Lackey, who began to grab at his bicep. Lackey’s next pitch ended up around Reyes’ ankles, and the veteran stumbled off the mound while grabbing his right arm.

At that moment, Lackey’s season — and perhaps career — came to a standstill. The months of rehab, getting into shape and then developing throughout spring training seemed lost. Now, we’re left wondering just how long the 34-year-old will be sidelined.

The Red Sox announced that Lackey suffered a biceps strain, which is actually a bit encouraging. The initial fear was that Lackey’s injury had something to do with his surgically repaired elbow, but that’s apparently not the case, and manager John Farrell even said after the game that the “cramp” Lackey suffered began to subside following the pitcher’s exit.

But while all of that is good news — all things considered — it doesn’t mean Lackey is off the hook. He’ll head to Boston to undergo an MRI on Sunday, and the Red Sox must figure out how to round out their rotation, assuming Lackey will miss some time.

The most likely scenario is that Alfredo Aceves will step in and assume the role of Boston’s fifth starter. He came on to pitch after Lackey left Saturday’s game, and gave up three earned runs — all on Colby Rasmus‘ mammoth three-run blast in the sixth — over 3 2/3 innings. Overall, Aceves’ outing yielded mixed results, but he’s the most logical choice for the time being.

Franklin Morales figured to be Boston’s spot starter this season, and he would have been a perfect fill-in, but the lefty is still out indefinitely with a back injury. Morales’ ailment is perhaps the biggest reason the Red Sox kept Aceves around, despite constant outside pressure from those sick of Aceves’ questionable behavior.

Aceves will turn heads with his wackiness, no doubt. In fact, it didn’t take long on Saturday, as he struggled to get on the same page with catcher David Ross, and then even fired a “pickoff attempt” over to Pedro Ciriaco while the shortstop was nowhere near the second base bag. The important thing for the Red Sox, however, will be whether or not Aceves produces.

If Aceves struggles, there’s a young pitcher by the name off Allen Webster waiting down at Triple-A. The Red Sox would ideally like to have Webster pitch a few more months in the minors before even considering bringing him up, but perhaps they’ll give into circumstance at some point, just as they did with Jackie Bradley Jr. In other words, the hard-throwing minor leaguer is one step closer to The Show, even though it’s under unfortunate circumstances.

Much of the Red Sox’ decision-making with regard to the rotation going forward will come after they have a clearer understanding of what Lackey’s future looks like. As of Saturday night, they’re just hoping for the best.

It’s one of the most cliche sayings in baseball, but you can never have enough pitching. It took just five games for the Red Sox to once again come to that realization.

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