Hector Rondon may be the most polarizing figure in the Cubs bullpen, if not the entire roster.

When he comes into games right now, a huge population of Cubs fans freak out on Twitter with some combination of annoyance, frustration or WTF reactions.

Look at the responses to this Tweet when he was called upon to pitch the seventh inning of Sunday night's win over the St. Louis Cardinals.

Quintana's day is done. Hector Rondon on to pitch the 7th for Cubs now. — Cubs Talk (@NBCSCubs) July 24, 2017

But how is that possible? Exactly a year ago, he was the dominant closer for the best team in baseball with a 1.95 ERA, 0.73 WHIP and 18 saves in 22 chances.

Rondon struggled down the stretch last season after the Cubs sent four players to New York for Aroldis Chapman and Rondon also had a triceps injury that limited him to just 11 games from Aug. 2 on.

In that span, the veteran right-hander struggled to get right with an ugly 12.46 ERA, allowing a .415 average and 1.272 OPS to opposing hitters.

Rondon was better in the postseason (4.50 ERA, 1.50 WHIP), but was pitching in low-leverage spots and was not one of Joe Maddon's trusted options in the World Series.

Could it all be because he was tipping his pitches?

Rondon acknowledges how the triceps issue could've affected his mechanics, but he actually thinks he was telegraphing his pitches too much and that was something he's had to work on correcting over the last year.

"I feel like we fixed the mechanics because we felt like last year, I was tipping some pitches," Rondon said, pointing to the way opposing batters hit him as the main reason for his line of thinking.

"Sometimes you can throw a really nasty pitch and they hit it and there's no reason to think they'll hit that pitch in that location. So you start to think that way. I think that's what it was."

Rondon admitted he feels really good right now, and the radar gun is showing it. He's throwing harder in July than he ever has before and hit 100 mph on the radar gun Sunday night.

Rondon hasn't hit 100 in a couple seasons and the last time he did so, he tipped his cap to his fellow relievers in the Cubs bullpen. But he's not settling just for 100 now.

"My goal is to hit 101 mph this year and then I'll tip my cap to them again," he said, smiling.

Rondon's confidence has also been a big factor ever since the Chapman move and it's something Maddon has been particularly focused on this season.

Rondon was pitching at a high level, then was demoted from closer for Chapman, then bypassed for the closer's role again this offseason as the Cubs traded for Wade Davis. Not to mention the clear lack of confidence Maddon had in Rondon last fall.

So when Maddon turned to Rondon with the bases loaded and nobody out in that disastrous eighth inning Friday afternoon and the end result was cringeworthy, the Cubs manager instantly took the blame for that.

"I immediately went up to him and I told him, 'I put you in a bad spot, brother. Please throw that one away,'" Maddon said. "I wanted him to know, 'Listen, you're throwing the ball way too well to worry about that moment.'"

With a two-run lead in the seventh inning of the rubber game against the Cardinals Sunday night, Maddon again called on Rondon and despite a walk and an infield hit, Rondon escaped the inning unscatched for his career-high eighth hold.

"He came out and I got right in his face in that moment and said, 'Man, that is IT. Now I just want you to focus on making pitches and believe that you're gonna make the pitch that you want to make,'" Maddon said. "His stuff [Sunday] was as good as I've ever seen it. Ever.

"You stand [in the dugout] that close to the hitter, you can really see that jump at home plate with guys with the really elite fastballs. And that's what I saw [Sunday] night. Now throw that elite fastball where you want to and heads up. 'Cause the slider's back."

Even with Friday's performance (four earned runs without recording an out), Rondon is sporting a 3.86 ERA since June 14 with 19 strikeouts in 14 innings.

Take that Friday game out of it and Rondon's numbers look like this for the last five weeks: 1.29 ERA, 1.00 WHIP.

Rondon has also been chatting a lot with Davis, a wise former starter who has morphed into one of the most dominant relievers on the planet for the last half-decade. One of the things the two veterans have been discussing is how to harness the elite-level stuff Rondon possesses.

"It's a good relationship and I'm glad to hear that specifically because that's exactly what Ronnie needs to do — go out there with a plan, as opposed to just going out there, winding up and throwing a pitch and hoping it doesn't get hit," Maddon said.

"[He needs to be focused on hitting spots.] 'I want it there. I want it there.' When he does that, heads up, because it's gonna be lights out."