Free-agent reliever Adam Ottavino and the New York Yankees agreed to a three-year, $27 million deal Thursday, league sources told ESPN, fortifying an already deep bullpen with a strikeout-happy right-hander who was one of the best setup men in baseball last season.

As a lockdown reliever for the Colorado Rockies last season, Ottavino struck out 112 batters, which ranked fourth among all MLB relievers, and held opposing hitters to a .158 batting average in 77⅔ innings. He went 6-4 with a 2.43 ERA as the Rockies reached the National League Division Series as the wild card before losing to Milwaukee.

Ottavino, 33, whose deal is pending a physical, joins the best bullpen in baseball. The Yankees now boast closer Aroldis Chapman, setup man Dellin Betances and late-inning specialist Zach Britton, who agreed to a three-year, $39 million deal with New York earlier this offseason.

Add in Chad Green and Jonathan Holder, who had a breakout 2018, and the Yankees' bullpen stands in stark contrast to that of the rival Boston Red Sox, who lost setup man Joe Kelly via free agency to the Los Angeles Dodgers and are without a closer, as Craig Kimbrel remains a free agent.

The Yankees' bullpen, which is coming off a season in which it was the first in MLB history to strike out more than 30 percent of batters faced (30.2), could be even tougher in 2019. It will feature three of the top 11 MLB relievers in strikeout ratio from 2018 -- and that's not including Britton, who has a career ratio of 8.7 K/9 IP as a reliever.

Ottavino, who earned $7 million while serving as the setup man for Rockies closer Wade Davis, has always been a great matchup option facing right-handed hitters but has continued to flash the right pitches to get lefty hitters out, too.

Strike Force The Yankees' bullpen next season will boast three of the top 11 pitchers in terms of strikeout ratio from 2018. '19 Yankees K/9 IP RP rank Aroldis Chapman 16.3 1st Dellin Betances 15.5 3rd Adam Ottavino 13.0 11th >>Min. 50 IP

He's prized for great control of his two-seamer and slider, both of which allowed him to thrive as he struck out 13 batters per nine innings and returned from Tommy John surgery on his right elbow. The procedure was performed in May 2015.

Ottavino also doesn't lack confidence, telling MLB's Statcast podcast in December that he "would strike out Babe Ruth every time."

"I had an argument with a coach in Triple-A about Babe Ruth's effectiveness in today's game," Ottavino said. "I said, 'Babe Ruth, with that swing, swinging that bat, I got him hitting .140 with eight homers.' ... I'm like, 'I would strike Babe Ruth out every time.'

"I'm not trying to disrespect him, you know, rest in peace, you know, shoutout to Babe Ruth. But it was a different game. I mean, the guy ate hot dogs and drank beer and did whatever he did. It was just a different game."

Ottavino is the only pitcher in MLB history to wear the uniform No. 0. Should he continue to wear it for the Yankees, he will have found the only single-digit number remaining in the Bronx. Nos. 1-9 have all been retired by the Yankees, most recently Derek Jeter's No. 2 in 2017.

Ottavino becomes the third former Rockies player to sign with the Yankees this offseason, joining shortstop Troy Tulowitzki and infielder DJ LeMahieu.

A first-round pick by the St. Louis Cardinals in the 2006 amateur draft, Ottavino made his major league debut four years later before being acquired off waivers by Colorado in 2012.

Over his career, Ottavino is 17-20 with 17 saves, a 3.68 ERA and 464 strikeouts in 413 innings.