After designating Josh Smoker for assignment, the Mets traded the southpaw to the Pittsburgh Pirates earlier this week.

The decision to remove him from the 40-man roster and then subsequently trade him was mind-boggling.

While it’s true that the Mets farm system has a lot of talented relievers currently developing in the minor leagues, Smoker was the only left-handed MLB-ready option, and despite his rocky MLB career thus far, there are enough positives that he was worth keeping around.

In 71.2 innings, Smoker has put up an exceptional 11.68 K/9 and has been able to retire both lefties (25.5 strikeout percent) and righties (30.4 strikeout percent). He does have issues with walks and home runs, but left-handed relievers who throw in the mid-90s and strikeout over 11 batters per nine innings don’t grow on trees.

Someone like Matt Reynolds would have had a better chance of making it through waivers.

With the Mets adding an infielder, Jose Reyes, while already have 10 other infielders on the 40-man, you would think they’d cut their weakest infielder and replace him with a not-quite-as-bad infielder, right? Apparently not. Yes, they have Jerry Blevins, and he’s been very reliable in his tenure with the Mets, but he can’t pitch every day.

Before they got rid of Smoker, it looked like he had a very good chance of being the second lefty in the bullpen. He quietly had a very good second half last year, with a 2.63 ERA, and was dominant in the final two months with 12.71 K/9 vs. only a 2.38 BB/9, and a 2.54 FIP. He has also been quite good in high leverage situations in his career, with 12.46 K/9, a 1.77 FIP, 2.99 xFIP and 1.04 WHIP.

While Smoker still has issues to work out before he can be fully trusted at the highest level, there were still plenty of signs that he was coming around. Even with his flaws, the Mets have no one better to take his spot. In fact, with the 40-man roster full now, they’re just going to have to make due with only one left-handed reliever unless they decide to DFA or trade Reynolds or even former first-round pick Gavin Cecchini.

With the Mets’ starting pitchers on shorter leashes this year and a bullpen that had the worst ERA in the National League last year, depth, versatility and talent within the bullpen are going to be vital to the team’s success, and they just got rid of an immensely talented, hard-throwing reliever.

Even if the Mets decide to do some roster-manipulating to clear a spot for a left-handed reliever, unless they actually decide to spend money on someone like Tony Watson, who could they call up?

Behind Blevins on the depth chart of left-handed relievers is Kyle Regnault, who has put up good minor league numbers but doesn’t have the stuff or the experience that Smoker has, Kelly Secrest, who has only pitched seven Triple-A innings, and David Roseboom, who had an 8.31 ERA in Triple-A last year.

They acquired Daniel Zamora in the trade for Smoker, but he’s still never pitched more than three innings in Double-A, so it’s unlikely that he’ll be Major League ready at any point this year. And that’s pretty much it.

Hopefully, some of the other young guys like Paul Sewald and Hansel Robles in the bullpen will continue to improve, and maybe if they’re lucky someone like Regnault or Secrest will break out and contribute to the Major League team.