Wade LeBlanc has authored one of baseball's most surprising seasons, and is part of the reason the Seattle Mariners seem assured a playoff spot for the first time since 2001.

On Tuesday, the M's rewarded LeBlanc by signing him to an extension. LeBlanc will receive a guaranteed $2.75 million in 2019 while the Mariners have potentially extended their control over him by three seasons:

LeBlanc has thus far tossed 72 innings, accumulating a 3.38 ERA (118 ERA+) and a 3.73 strikeout-to-walk ratio. The command-and-control artist has done well to limit his free passes, walking fewer than two batters per nine innings. It's worth noting the Mariners have done well to prevent overexposure, tasking him with just 5.3 innings per start.

The deal carries little risk for the Mariners, considering LeBlanc was already under team control for next season. Given his season to date, it was all but a given that he would be tendered and return to Seattle. As such, this deal is about gaining additional control -- a potentially worthwhile endeavor, should LeBlanc prove this season wasn't a fluke.

At minimum, extending LeBlanc seems to lock in the Mariners' 2019 rotation. Felix Hernandez has one more year remaining on his contract and seems like a sure thing for the rotation regardless of his performance. Mike Leake is in a similar boat, albeit with more than one year left on his deal. Then there's James Paxton and Marco Gonzales, and each will be under team control for at least two more seasons. Add in LeBlanc and that gives the M's five starter candidates. (Erasmo Ramirez, who has one year of team control left, could in theory serve as a swingman.)

LeBlanc has appeared in part of 10 big-league seasons, pitching for seven teams. His career figures include a 4.29 ERA (91 ERA+) and 2.29 strikeout-to-walk ratio.