Miller left Wednesday's game against the Rockies with right elbow tightness.

EDGE Analysis

It's quite the worrisome development for a pitcher who only recently returned from Tommy John surgery, as "elbow tightness" is sometimes the original diagnosis which precedes a serious injury. Miller certainly didn't look good on the mound, allowing five runs in just one inning. The severity of the injury should become clear in the next few days.

Miller (elbow) has been activated from the disabled list, and will make his season debut Monday night against the Marlins.

EDGE Analysis

Miller has been out of action since undergoing Tommy John surgery May 10, 2017, but he is ready to return to action after completing both his recovery and a rehab assignment. Miller threw 81 pitches in his final rehab start last week, and he doesn't figure to be extended too much beyond that in his first MLB start in over 14 months.

Miller (elbow) will be activated from the 60-day disabled list to start Monday against the Marlins, Steve Gilbert of MLB.com reports.

EDGE Analysis

Miller has been cleared to make his long-awaited 2018 big-league debut after completing a lengthy recovery process that included a four-game rehab assignment. He posted a 4.66 ERA and 28:6 K:BB across 19.1 innings across those four outings (two with Double-A Jackson, two with High-A Visalia). The right-hander, who hasn't pitched in the majors since April of 2017 due to an elbow injury that ultimately required Tommy John surgery, will assume the rotation spot of Matt Koch, who was sent to the minors Wednesday. With Robbie Ray (oblique) also nearing a return from the disabled list, Miller may need to pitch well right away if he wants to stick in the rotation.

Miller (elbow) completed a 40-pitch bullpen session Tuesday and could assume Matt Koch's spot in the Arizona rotation when the latter's next scheduled turn comes up Monday in Miami, Zach Buchanan of The Athletic Arizona reports.

EDGE Analysis

Koch was tagged for five runs in 5.2 innings while taking the loss Tuesday against the Angels, inflating his ERA to 6.10 over his last seven outings. Though he's been a serviceable innings eater since replacing the injured Taijuan Walker (elbow) in mid-April, Koch's lack of strikeout stuff and flyball-heavy tendencies don't give him nearly the upside nor the stability of Miller, who has three seasons of sub-4.00 ERAs on his resume and whiffed 10 batters over 6.2 innings in his most recent rehab start at High-A Visalia last weekend. Since Miller only threw 81 pitches in that outing, it's possible the Diamondbacks may want him to exceed the 90-pitch threshold in another minor-league start before returning to the big club, but his reinstatement is imminent nonetheless. Once he's activated, Miller may need to perform well right away to bolster his case for sticking in the rotation, as Robbie Ray (oblique) isn't far off a return from the DL either.

Miller (elbow) worked 6.2 scoreless innings in a rehab start Saturday for High-A Visalia, giving up three hits and no walks and striking out 10.

EDGE Analysis

After being tagged for eight runs his last time out June 10 at Double-A Jackson, Miller bounced back in grand fashion Saturday in what might have been his final rehab start. The right-hander tossed 81 pitches in the outing and used his full arsenal, putting him on the cusp of a return from the 60-day disabled list. It's not immediately clear if Miller will reclaim a rotation spot once he returns from the DL, however, as the Diamondbacks have gotten quality performances from back-end starters Matt Koch and Clay Buchholz over the last few weeks and may be reluctant to move either to the bullpen.

Miller (elbow) will start for High-A Visalia on Saturday, Jack Magruder of The Sports Xchange reports.

EDGE Analysis

Miller has already made a trio of rehab starts so far, allowing 10 runs while striking out 18 across 12.2 innings during those outings. He's set to make at least two more rehab appearances before potentially being activated from the 60-day disabled list, lining him up for a return near the end of June if all goes well. That said, Miller may not be guaranteed a spot in the Diamondbacks' rotation once healthy if Zack Godley, Matt Koch and Clay Buchholz are all pitching well.

Miller (elbow) is expected to make at least two more rehab outings in the minors before being activated from the 60-day disabled list, Zach Buchanan of The Athletic Arizona reports.

EDGE Analysis

Miller was expected to build up to around 90 pitches in his third rehab start Sunday at Double-A Jackson, but he only made it 65 while being clobbered for eight runs on nine hits and two walks over three innings. The right-hander didn't report any setbacks with his surgically repaired elbow coming out of the poor start, but he'll require a couple more turns in the minors to build up to a starter's workload. Miller doesn't look on track to return from the DL until late June and may not be guaranteed a spot in the Arizona rotation if all of Zack Godley, Matt Koch and Clay Buchholz are pitching well.

Diamondbacks manager Torey Lovullo said Tuesday that Miller (elbow) would remain on assignment at Double-A Jackson for at least one more rehab start, the Associated Press reports.

EDGE Analysis

Lovullo noted that Miller didn't experience any unusual soreness with his surgically repaired right elbow after completed his first start at Jackson and second turn in the minors overall Monday. Miller, who tossed 79 pitches during that outing while giving up one run and striking out six over 4.2 innings, is expected to build up to 90 pitches in his upcoming start for Jackson, which will likely fall Saturday or Sunday. Assuming he comes out of that appearance no worse for the wear, Miller would presumably get activated from the 60-day disabled list and slot back into the Arizona rotation for the first time since April 2017.

Miller (elbow) made his second rehab start at Double-A Jackson on Monday, tossing 4.2 innings of one-run ball and scattering four hits and four walks. He struck out six batters in the outing.

EDGE Analysis

Despite the high walk total, Miller still pounded the zone effectively Monday, tossing 52 of his 79 pitches for strikes. The Diamondbacks will probably want to see Miller build up to 90 pitches before deeming him ready to return from the 60-day disabled list, so it seems likely that he'll require one more start in the minors. Assuming Miller is activated around mid-June, he could slide into the Arizona rotation, though the strong performances of late from Nos. 4 and 5 starters Matt Koch and Clay Buchholz, respectively, make that less of a certainty than it appeared to be a couple weeks ago.

Miller is scheduled to make his next rehab appearance Monday for Double-A Jackson, the Associated Press reports.

EDGE Analysis

Miller will be pitching on six days' rest after tossing five innings of one-run ball and striking out eight in his first rehab appearance for High-A Visalia on May 29. Miller threw 65 pitches in that outing, so he'll presumably bump his count up closer to the 70-to-80 range as he builds his arm back up following a year-plus layoff due to Tommy John surgery. The Diamondbacks will likely wait and see how Miller looks during Monday's outing before determining if another rehab start is necessary or if he's ready to return from the 60-day disabled list and rejoin the big club.