PHILADELPHIA -- The Phillies are making their push to sign free-agent left-hander Patrick Corbin.
Corbin visited Citizens Bank Park on Tuesday, sources confirmed to MLB.com, as the Phillies hope to add the pitcher to their rotation. Chris Jones from the Twitter account @LONG_DRIVE broke the news and tweeted a photo of Corbin in a Phillies cap on the Phanavision scoreboard. The Phillies want Corbin because he is arguably the best free-agent pitcher available and they want to balance out their rotation, which has had only three starts from a left-hander since the end of the 2016 season.
Adding Corbin would be a significant first step in what is expected to be a big offseason for the Phillies.

"In a perfect world, we would like to have a balanced rotation," Phillies general manager Matt Klentak said in early November at the General Managers Meetings in Carlsbad, Calif.
"Now, what we're not going to do is swap out a good righty for a less-good lefty. We're not going to do it just to create balance. But if we can keep the rotation as good as it is or make it better and also add balance to our pitching staff, I think that's something worth exploring. I don't know if we'll actually do that, but I know that we will explore it."
Corbin, 29, went 11-7 with a 3.15 ERA in 33 starts last season with the D-backs. He struck out 246 batters in 200 innings and posted a 6.3 FanGraphs WAR. Corbin also finished fifth in National League Cy Young Award voting, two spots behind Phils ace and third-place-finisher Aaron Nola.

Corbin has one of the best sliders in baseball. He threw the pitch 40.9 percent of the time in 2018, and opponents hit just .145 and slugged just .243 against it. MLB.com's David Adler wrote in October that Corbin struck out 196 batters with his slider -- 71 more strikeouts than any other pitcher. He also got 387 swings-and-misses on his slider -- 176 more than any other pitcher.
No pitcher in baseball owns that large a margin in strikeouts or swings-and-misses on any other pitch.
Corbin and fellow left-hander J.A. Happ, 36, might be atop the Phillies' starting-pitching wish list, although Philly has inquired about a potential trade for Giants ace Madison Bumgarner and expressed interest in others, like Nathan Eovaldi. Happ could be looking for a three-year deal. Corbin is almost certainly looking for more, perhaps at least a five-year, $100 million contract. If the Phils give Corbin what he wants, it would be a departure from Klentak's public reluctance to commit long term to pitchers.
Corbin carries risks, in that he is less accomplished than other top-of-the-rotation starters the Phillies acquired in the recent past, like Roy Halladay, Cliff Lee and Roy Oswalt. Corbin missed 2014 and part of '15 following Tommy John surgery on his left elbow. He went 19-26 with a 4.53 ERA and a 4.42 FIP from '16-17 before hitting his stride in '18.
But Corbin would fit nicely between Nola and right-hander Jacob Arrieta atop the Phillies' rotation. It would allow the Phils to move forward with their other offseason plans to bolster the offense and bullpen. Philadelphia has interest in relievers Craig Kimbrel, Zach Britton and Andrew Miller, and it is considered a favorite to land Bryce Harper or Manny Machado, although those players are not stopping the club from looking for other ways to upgrade. MLB.com's Jon Paul Morosi recently wrote that the Phillies have expressed interested in free agent Michael Brantley and A.J. Pollock, as well as others.