Baseball’s 2021 saves leader Mark Melancon is joining the Arizona Diamondbacks, the team announced Wednesday. The deal came down less than eight hours before the start of a league-wide lockout that has now suspended major league transactions indefinitely.

Melancon will make $6 million in both 2022 and 2023. The deal also includes a $5 million mutual option for 2024 with a $2 million buyout.

That may not sound like a lot, but the total guarantee of $14 million is the highest amount given to a free-agent reliever in franchise history. Like I wrote recently, the D-backs historically have spent very little on their bullpen compared to other teams.

Melancon spent 2021 as the closer for the San Diego Padres, where he secured his fourth career All-Star appearance on his way to an impressive 2.23 ERA, 1.22 WHIP, 59 strikeouts and 25 walks over 64.2 innings. Melancon had 39 saves in 45 opportunities.

As he transitions to the desert, here’s what to expect.

A clear upgrade

At first glance, Melancon is similar to other Diamondbacks closers of the Mike Hazen era. Melancon will be 37 when the season starts, which is precisely the same age as the team’s 2021 Opening Day closer, Joakim Soria. Much like Soria, Melancon is also not overpowering, relying primarily on a 92 mph cutter and an 82 mph knuckle-curve.

What sets Melancon apart is that he’s not far past his prime, if at all. The velocity on his legendary cutter has held steady for more than six years, and his 22.3 percent strikeout rate in 2021 was actually a tick above his career average.

A lot of groundballs

Even if Melancon’s strikeout rate dips as he inches closer to age 40, he’s never relied on whiffs to get outs. His 56.4 percent groundball rate this season was the 14th highest mark in baseball among relievers with 50 or more innings pitched. For reference, the D-backs’ bullpen posted a 40.8 percent groundball rate in 2021, the sixth-lowest mark in baseball.

It’s important to note that inducing a lot of groundballs doesn’t necessarily equate to positive results. D-backs reliever Matt Peacock actually had a higher groundball rate than Melancon in 2021 at 59.7 percent. He also posted a lackluster 4.64 ERA.

The difference is that unlike Melancon, Peacock almost never strikes anyone out. His 13.0 percent strikeout rate in 2021 was untenable for a major league reliever. Melancon gets his whiffs, but he also keeps the ball on the ground.

Of course, more groundballs means fewer balls in the air, and fewer balls in the air means fewer home runs. That’s good news for a bullpen that allowed the sixth-most long balls in baseball last year. Melancon hasn’t allowed more than four home runs in a season since 2012.

Durability

Melancon hasn’t dealt with a significant injury since 2018. Since securing his first full-time role in the big leagues in 2011 with the Houston Astros, Melancon has tossed 633 innings in 11 seasons. That’s the sixth-most among relievers in that span, trailing only Steve Cishek, Tony Watson, Bryan Shaw, Tyler Clippard and Kenley Jansen.

Melancon’s ability to produce consistent results and stay on the field puts him in a rare category. Among active players, Melancon’s 244 career saves is fourth in baseball, trailing only Craig Kimbrel, Kenley Jansen and Aroldis Chapman. It is not out of the question that Melancon could break 300 saves during his time in the desert.

If we’re nitpicking, the only concerning trend in Melancon’s game is a steady increase in walk rate over the last several years. In 2021, Melancon issued free passes to 9.4 percent of opposing hitters, which was the highest mark of his career. That being said, that number is still respectable, and command has never been a significant issue for him.

Even so, it may be unrealistic to expect an ERA as low as 2.23 again from Melancon. While he was genuinely very good in 2021, more advanced metrics suggest he overperformed. His xFIP, for example, came in at 3.45. An ERA in that range is likely more in line with what we should expect from him moving forward.

One thing is certain, though: Mark Melancon is already the most well-established free-agent reliever the team has signed in more than a decade.