MESA, Ariz. — Cubs fans, it’s time to put Shelby Miller firmly on your radar.

Unprompted, Miller’s teammates have brought up how impressed they’ve been by his performance this spring.

“I saw Shelby Miller today throwing a bullpen — he was nasty,” Pedro Strop said last week.

When asked about pitchers who could impact the 2021 rotation, Jake Arrieta’s mind immediately went to Miller.

“I love what I’ve seen out of Shelby,” Arrieta said.

More importantly, coaches have taken notice as Miller — who is in camp on a minor-league deal — fights for a spot on the Opening Day staff.

“My impression of him has been awesome,” pitching coach Tommy Hottovy said. “Shelby’s one of those guys — he just looks the part. He’s athletic, he’s got all the pitches and he has the track record of doing it in the past. He’s been great to work with.”

Miller tossed 2 scoreless innings in Monday’s game against the White Sox, striking out 3. That lowered his spring ERA to 1.29 and he has 8 strikeouts in 7 innings.

The Cubs are considering him for a number of different roles — starter, long man out of the bullpen, 1-inning reliever. If he earns a spot on the roster out of camp, it’s likely he would make an impact in both the rotation and bullpen as the Cubs work to cover innings and manage workloads following the pandemic-shortened season.

“You could talk about him being in the middle of two guys in a series, you could talk about him coming in after a starter and throwing 3 innings,” Hottovy said. “There’s a lot of things you could do with a guy like that.

“We like the way he’s progressing, we like the stuff he’s talking about. He’s very open with a lot of the communication stuff we want to present to him. Just really anxious and excited to get to see him more often as we get through camp.”

Once upon a time, the 30-year-old was one of the top pitching prospects in baseball coming up with the St. Louis Cardinals. He was the 19th overall pick in the 2009 Amateur Draft and found himself in the Top 10 on Baseball America’s prospect rankings in back-to-back years (2012-13).

He has been the headliner in separate trades for Jason Heyward and Dansby Swanson as he was dealt from the Cardinals to the Braves to the Diamondbacks.

From 2012-15, he had a 3.22 ERA and 1.24 WHIP over 102 appearances (96 starts) and made the National League All-Star team in 2015 as a 24-year-old.

A mix of injuries and ineffectiveness derailed his career path from there as he’s pitched in just 48 MLB games with a 6.89 ERA since 2015.

Miller spent the 2020 summer camp with the Milwaukee Brewers and after he was sent to the alternate site to begin the shortened season, he decided to opt out. His wife had just had a baby and he was sitting in a hotel room wondering why he wasn’t at home with his two-week-old son, Kyler.

So Miller went back to Phoenix for the fall and winter and regularly threw bullpens in an effort to be ready for 2021.

“I’ve spent this whole offseason trying to get back to the old version of myself where I had a little bit more life on my fastball,” Miller said. “…I’ve had people tell me to change ways back in the day and the past couple years that weren’t necessarily what made me good — not that that’s their fault. It’s my career.

“[Now, my focus is on] getting back to what works and what makes me successful on the mound. I sit down with these guys in the video room and we go over all that and it’s really useful. We’re just trying to replicate that and get back to being the best I can.”

While he didn’t pitch in a game last season, 2020 was not a wash for Miller. About a week before he opted out, he started working on a slider and that pitch has emerged as a gamechanger for him this spring.

“[I’m] pretty confident in it,” Miller said. “I’ve never really had a pitch that I could throw and get a lot of swings and misses on. This spring, I’ve been throwing it live to hitters without even thinking about it and I’ve been getting good results.

“I’m all about seeing how far that could take me. If I get two strikes on guys, I feel like I have an out pitch and whether it’s my fastball up or slider down or whatever the case is, I feel like having two options is just gonna help me a ton this year.”

Miller always felt like he was more of a power pitcher in his younger days and his fastball still sits in the mid-90s. Adding the slider gives the opposition something else to think about.

“One of the advantages I have right now in camp against the opposing hitters is that they have to respect a whole other pitch that they haven’t seen,” Miller said. “I’m just gonna keep throwing it and hoping it gets better.”

Right now, the story around Miller is in the short term and what kind of role he fills on the 2021 Cubs staff. But he’s also thinking more big picture.

“Whatever I can do to help the team,” he said. “I’ve always been a guy who’s willing to adapt and try anything.

“Obviously I’d love a roster spot and to be a part of the Chicago Cubs organization for a while. These guys that are here have been amazing. Whatever happens, happens. We’ll see.”