As Jed Hoyer’s front office begins to devise a plan of attack for the offseason, the Cubs first need to determine what they have before they can go after what they need.

We know pitching is going to be a top priority — specifically starting pitching.

So what do the Cubs have already in the starting rotation?

There’s Kyle Hendricks.

After that?

A bunch of question marks.

Adbert Alzolay, Justin Steele and Keegan Thompson are going to be a big part of the pitching staff in 2022, but we don’t know in what capacity. All three youngsters performed well in the bullpen in 2021 and had mixed results as starters.

Veteran Adrian Sampson impressed down the stretch and may serve in a swingman capacity out of the bullpen and as rotation depth heading into next season.

Will Alec Mills fill the same role?

The 29-year-old right-hander just wrapped up his first full season in the big leagues, which seems a little hard to believe given how much he’s been through in his career to date — 62 appearances over parts of four seasons and a no-hitter against the Brewers last September.

He began 2021 in the bullpen, serving in both short stints and multi-inning outings. A lower back strain put him on the IL for almost a month in May and June and when he returned, he made 1 appearance as a reliever before being inserted into the rotation.

At a time when the Cubs were desperately searching for length from their starters, Mills delivered and brought some stability to the pitching staff.

Over a 13-start stretch from mid-June through the end of August, he had a 3.68 ERA and 3.26 FIP (Fielding Independent Pitching) while averaging more than 5 innings per outing (which included a rain-shortened start Aug. 10).

Mills struggled in September, posting a 7.82 ERA in his first 5 starts, allowing at least 4 runs in every outing but 1.

Could some of that be attributed to pitching in September of a 162-game season for the first time?

“I don’t really like saying I was wearing down,” Mills said after the Cubs’ season finale Sunday. “That’s just an excuse and I don’t try to make excuses. I think a lot of it, to me, honestly was maybe falling into some patterns that they had seen all year. Even good pitches that were thrown were still getting hit because it was a pitch I had been throwing all year and they were sitting on certain things.”

He felt like he made some adjustments and got back to a good place for his final start of 2021 against the Cardinals, when he allowed 2 runs in 4 innings.

In all, Mills is walking away from his 2021 campaign with a good perspective on how to approach the offseason.

“It’s been a lot of ups and downs,” Mills said. “It’s been a whirlwind, especially going from 60 to 162 and this being my first full year. It was a grind. The last month was not easy. It’s a marathon — I think we can say that until we run out of air. It really is. It’s a long season.

“For me, the main goal is to be healthy. That worked — ended the year healthy. It wasn’t the best finish to the year. Not pleased with how I finished out but maybe I’ll take that and be hungry going into the offseason ready to compete next year.”

While Mills has shown throughout his career that he could handle a variety of roles on a pitching staff, he’s been better as a starter than out of the bullpen.

He has a career 4.45 ERA in the rotation vs. a 5.24 mark as a reliever. There was an even larger gap between those two numbers in 2021 — 4.80 as a starter, 6.41 as a reliever.

The Cubs understand those splits, but they aren’t yet ready to write Mills’ name in pen for the 2022 rotation.

“He did a great job down the stretch this year,” Hoyer said. “In general, I try to think about this in terms of ability to impact our staff and certainly he’s gonna have a big part of that. I think the modern game or the way things are moving, locking in: here are five starting pitchers and here are eight relievers going forward. That’s not the way the game is played sometimes.

“I think Alec has a big role on our team [next] year. I think he’s best when he does start. I expect him to play a big role; I’m just reluctant to sit here and tick off one rotation spot after another because I think as we saw this year, it’s gonna take a lot more than five guys to get through this.”