CHICAGO -- Adbert Alzolay broke into a wide smile when asked Saturday about Justin Steele joining the Cubs rotation soon. It will be a chance for the pair of pitchers to prove they belong in the team's future plans.

"We were pitching in the same rotation for four years," Alzolay said of their days in Chicago's farm system together. "So for me, it's going to be special having one of my best friends next to me in the rotation at any time. Hopefully, sooner than later."

Sooner, indeed.

Prior to Sunday night's game against the White Sox, Cubs manager David Ross announced that Steele was poised for a promotion from Triple-A Iowa. The lefty is the planned starter for the North Siders for Tuesday's game against the rival Brewers.

Steele's arrival will serve two purposes: Allowing the Cubs the chance to evaluate him as a starter down the stretch and giving the team a way to taper innings for other arms. Chicago will shift to a six-man rotation with Steele in the fold.

"I think it's the smart thing to do with everybody," Cubs pitching coach Tommy Hottovy said. "Being on a six-man rotation, or being able to use off-days to move pieces around to give guys rest, I think is just an important part of, one, the development of guys for the rest of this year, but also maintaining the health and the workload."

Earlier this season, the Cubs gave Steele a taste of the big leagues as a reliever and he answered the call with a 2.03 ERA in 11 games (21 strikeouts vs. seven walks in 13 1/3 innings). After a stint on the injured list between May and June due to a right hamstring setback, Steele reported to Triple-A to build up as a starter.

In his last five starts, Steele has spun a 0.87 ERA with 27 strikeouts and nine walks in 20 2/3 innings. In that span, the lefty has surrendered just 11 hits (no home runs), limiting opposing Triple-A hitters to a .151 average (.431 OPS).

"He's done everything he needed to do to kind of show us his ability to be a starter and get stretched out," Hottovy said. "Now, we're just excited to get our hands on him and more of a one-on-one [setting]. ... I'm just excited to see him go out there and go two or three times through a lineup, and just continue to attack with some plus-plus stuff."

Other rotation notes

? Jake Arrieta, 35, has posted an 8.28 ERA in his last 14 turns, averaging fewer than four innings per start. Hottovy was asked Sunday what the goal is for the veteran pitcher down the stretch.

"Our goal with every one of these guys," Hottovy said, "is to continue to help them improve and get to the best version of themself. Again, whether they're going to be with us next year and they're developing for what we want to do, or they're going to be free agents next year, I want those guys going into the offseason feeling good about where they are, how they end the season, how things progress."

? Like the Cubs did with Steele, righty Keegan Thompson is currently being stretched out as a starter for Triple-A Iowa after a stay in the Cubs' bullpen. Through two starts, Thompson has logged 6 1/3 shutout innings with seven strikeouts and two hits allowed.

Hottovy said Thompson is still building up his pitch count and the Cubs will continue to evaluate the situation. In his most recent outing on Thursday, Thompson threw 52 pitches in 3 1/3 innings.

Down on the farm

? Outfielder Alexander Canario (No. 7 on MLB Pipeline's Top 30 Cubs prospects list) hit a homer for High-A South Bend on Saturday, and has hit .310/.375/.586 through seven games since being acquired from the Giants in the Kris Bryant trade.

? Outfielder Jordan Nwogu (third-round pick in the 2020 MLB Draft) went 3-for-6 for Low-A Myrtle Beach on Saturday. Nwogu has hit .364 with three homers, 10 RBIs and a 1.114 OPS in his last 14 games.

Quotable

"I think it's always important for big leaguers to go out there and play like big leaguers. The youth aspect of it just gives a freshness and a look for an organization that's got one eye on the future in the middle of trying to perform." -- Ross, on expectations for Steele down the stretch