Justin Grimm throws his curveball about the same speed as Dan Haren's fastball.
As he carved through the heart of the Detroit Tigers order last week (striking out all three batters he faced, including Miguel Cabrera and J.D. Martinez), Grimm was spinning his "offspeed" pitch around 85 mph while Haren has his self-deprecating @ithrow88 Twitter handle.
That illustrates the video-game-type stuff and numbers coming out of the bullpen, where Cubs manager Joe Maddon has used Grimm in almost any role imaginable.
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As the Cubs have gotten hot and made a serious push for the playoffs, Grimm and his 1.24 ERA has been leading the way out of the bullpen and he will be counted on even more now that Jason Motte has landed on the disabled list with a shoulder injury.
Grimm hasn't allowed a run in his last 15 games dating back to July 21, striking out 16 batters in 13 innings and picking up seven holds, two saves and a win in the process.
"What level is he pitching at right now?" Maddon said. "The kid's been good all year, but this is a little bit different.
"I'm happy for him. He's pitching outstanding baseball."
Maddon is careful not to attach any sort of labels onto each member of a successful bullpen, which ranks 12th in Major League Baseball with a 3.43 ERA. But Maddon did mention how important the fifth and sixth innings are and that he loves "middle-inning closers" like Grimm and lefty Travis Wood.
Grimm said he's gotten used to pitching without a defined role, knowing the bullpen phone can ring at any time and he needs to be ready to roll.
Grimm's 1.1 WAR ranks him 30th among MLB relievers on FanGraphs, even though he's pitched just 36.1 innings this season after missing the first month with a forearm injury.
He also ranks seventh in the big leagues with 13.13 strikeouts per nine innings, finding his name among dominant closers and setup men like Aroldis Chapman, Dellin Betances and Kenley Jansen and ahead of Craig Kimbrel, arguably the game's best reliever the last five seasons.
Grimm - who recently turned 27 - has always had the stuff, but he wasn't able to put it all together until last season.
For him, it always came down to one thing.
"Turning the corner at this level was all confidence," he said. "I was questioning if I belong at this level at first. I kinda took my own route in that aspect."
Grimm came up as a starter in the Texas Rangers minor-league system and made 19 starts for the organization in 2012-13 before he was moved to the bullpen.
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No matter how much success he's having as a reliever, Grimm hasn't given up hope on starting.
"I do like the bullpen. It's good, but I still believe I can start," he said. "I do. When I came up in the big leagues, I wasn't necessarily ready. So maybe moving to the bullpen, honestly, helped me adjust to the big leagues more than anything.
"The only thing I was missing when I was starting - it wasn't stuff. I wasn't making different pitches. It was just a confidence thing. When you're not throwing with confidence, you give up the big hits. You walk people.
"But now, I think I could be a quality starter for this team and in this league."
That being said, Grimm reiterated that he enjoys being a part of this bullpen right now, and starting is just something he hasn't shut the door on down the road.
Grimm knows if the Cubs are going to keep having success into October, they're going to need him to get some big outs, no matter the inning.