Arizona Diamondbacks place Jordan Montgomery to IL; Gabriel Moreno, Alek Thomas return

LOS ANGELES — The Arizona Diamondbacks placed left-hander Jordan Montgomery on the 15-day injured list with right knee inflammation Tuesday, an unexpected roster move amid a slew of more anticipated moves.

The club also activated catcher Gabriel Moreno and center fielder Alek Thomas, as expected. Moreno missed the minimum 10 days with a sprained thumb; Thomas had been on the injured list since the first week of the season with a hamstring strain.

To clear those roster spots, the Diamondbacks optioned infielder Blaze Alexander to Triple-A Reno and designated catcher Tucker Barnhart for assignment. Alexander started the season strong at the plate while struggling defensively but he was 4 for his past 34, even as his defense slowly improved.

With Alexander in Triple-A, Kevin Newman will take over his reps as the backup third baseman to Eugenio Suarez. Manager Torey Lovullo said the split could look similar to what it was between Suarez and Alexander. In recent weeks, Alexander had been getting roughly two starts per week. In Triple-A, Alexander will see time at all three infield positions, with a focus on third base.

The Montgomery news, though, was the most surprising of the day’s flurry of moves. He has struggled mightily this season since signing a one-year, $25 million deal just before Opening Day. That deal includes a player option that Montgomery now appears more likely to consider than when the contract was signed. He has a 6.44 ERA and allowed eight runs (seven earned) in 2 2/3 innings against the Twins last time out.

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His discomfort popped up in a bullpen session over the weekend, Lovullo said.

"It wasn't making a pitch," Lovullo said. "He was just walking back up to the rubber to continue his bullpen and he felt a little discomfort so he shut it down."

MRI results showed inflammation in Montgomery's patellar tendon but nothing more significant, prompting optimism that his absence could be a short-term one — potentially as brief as the minimum 15 days on the injured list.

"We've gotta get that inflammation down," Lovullo said. "Anti-inflammatories, that type of stuff. So get that inflammation down to where he can get back out there and function without feeling the discomfort."

Although Montgomery has pitched poorly, the Diamondbacks have seen equally bad production out of their young rotation depth. In an attempt to change, they appear set to turn to prospect Cristian Mena to start Wednesday's game against the Dodgers. Mena was in the visiting clubhouse Tuesday afternoon, although the club could not officially announce him as Wednesday's starter.

Mena, who was acquired in an off-season trade that sent Dominic Fletcher to the White Sox, is the club's third-ranked pitching prospect and 11th overall prospect, per MLB.com. He began the season strong in Triple-A but has struggled over the past month, with a 7.16 ERA in his past six starts.

"He deserves the opportunity," Lovullo said. "He is continuing to grow and learn. He's a young starting pitcher, he's had a lot of really good moments. We feel like he can change speeds, work the ball around the zone and follow a game plan."

In the meantime, the Diamondbacks filled Montgomery's spot on the roster by recalling right-hander Gavin Hollowell from Reno. They claimed Hollowell off waivers from the Rockies last month. He has pitched four scoreless outings in Triple-A since joining the organization.

Tuesday’s Diamondbacks-Dodgers pitching matchup

Diamondbacks at Dodgers, 7:10 p.m., Cox, Ch. 34

Diamondbacks RHP Joe Mantiply (3-1, 4.11) vs. Dodgers RHP Bobby Miller (1-1, 6.75).

At Dodger Stadium: Ryne Nelson initially was scheduled to start, but Mantiply was slotted in Tuesday from his regular relief role. The move came the same day the team announced pitcher Jordan Montgomery who has struggled this season, was headed to the 15-day injured list with right knee inflammation. Mantiply has appeared in 37 games and pitched 30⅔ innings … Miller made three starts before landing on the injured list in April with right shoulder inflammation. He has made two starts since returning, going 6⅓ innings against the Rockies but lasting only two innings against the White Sox in his most recent performance. … Miller has a 3.00 ERA in two career starts against the Diamondbacks. That is not counting his start last year in Game 2 of the division series, in which he gave up three runs in 1⅔ innings.

Wednesday's Diamondbacks-Dodgers pitching matchup

Diamondbacks at Dodgers, 7:10 p.m., Cox, Ch. 34

Diamondbacks Cristian Mena (3-2, 4.90 in Triple-A) vs. Dodgers RHP Gavin Stone (9-2, 2.73).

Mena had a locker at Dodger Stadium on Tuesday and appears set to start Wednesday’s game in place of injured LHP Jordan Montgomery.  … He was acquired from the White Sox for OF Dominic Fletcher in the offseason. … He is considered one of the club’s more promising pitching prospects. … He started the season well in Triple-A but has a 7.16 ERA over his past six starts. ... Stone, a former top-100 prospect, has excelled in his second season in the big leagues. ... He pitched a four-hit shutout against the White Sox last time out and had a 1.97 ERA in June. ... His changeup and slider are both putaway pitches, while his 94.6 mph fastball has gotten excellent results this season.

Coming up

Thursday: At Los Angeles, 6:10 p.m., Diamondbacks RHP Zac Gallen (6-4, 2.83) vs. Dodgers RHP Landon Knack (1-1, 2.08).

Friday: At San Diego, 6:40 p.m., Diamondbacks RHP Slade Cecconi (2-6, 5.81) vs. Padres RHP Matt Waldron (5-7, 3.56).

Saturday: At San Diego, 6:40 p.m., Diamondbacks RHP Brandon Pfaadt (3-6, 4.28) vs. Padres TBA.

What to know about the Los Angeles Dodgers

The Dodgers entered Monday with the second-best win percentage (.612) in the National League and the fifth-best in the majors. They have been playing without SS Mookie Betts since June 16, but they are 8-4 in that time, averaging six runs per game as an offense. They are also without 3B Max Muncy, who has been on the injured list since mid-May due to an oblique strain. DH Shohei Ohtani has been one of the better hitters in the majors this year, with a .316/.399/.635 line and an NL-best 26 homers. 1B Freddie Freeman had a huge June, slashing .319/.416/.617 with six homers in 26 games. The Dodgers recently brought RHP Bobby Miller back from the injured list but are again without RHP Walker Buehler, who made eight starts in his return from elbow surgery before going down with a hip injury. LHP Clayton Kershaw also remains out as he works his way back from offseason shoulder surgery.