Jameson allowed a hit and a walk over two scoreless innings in Saturday's spring game against Oakland.

EDGE Analysis

Jameson and Ryne Nelson, the two leading candidates for Arizona's fifth-starter job, started split-squad contests Saturday. After round one, Jameson has the edge, as Nelson was knocked around by the Rockies for four runs in one-plus innings.

Jameson will start on the mound for Arizona in Saturday's game against Oakland, Theo Mackie of The Arizona Republic reports.

EDGE Analysis

Jameson turned a few heads in his brief major-league stint last season, posting a 1.48 ERA and 1.11 WHIP through 24.1 frames in four starts. He figures to be one of the primary candidates for the fifth spot in Arizona's rotation alongside Ryne Nelson, who will start in the D-backs' other split-squad matchup Saturday against Colorado.

Jameson is expected to compete for the No. 5 starter job this spring, Nick Piecoro of the Arizona Republic reports.

EDGE Analysis

Jameson started 2022 at Double-A Amarillo before moving onto Triple-A Reno and was effective in a four-start stint with the Diamondbacks. The 25-year-old right-hander pitched to 1.48 ERA over 24.1 innings and threw at least six innings in three of his four starts. He and Ryne Nelson are considered the top candidates for the rotation, ahead of Tommy Henry and Brandon Pfaadt.

Jameson (3-0) earned the win Saturday, allowing two runs on six hits and two walks over six innings against the Giants. He struck out seven.

EDGE Analysis

Jameson's biggest mistake came on a solo home run from third baseman J.D. Davis with two outs in the sixth inning to cut Arizona's lead to 3-2. This was just the fourth major-league start of the 25-year-old's career, and he has allowed two runs or fewer in all four with three of them being quality starts.

Jameson did not factor into the decision Sunday, allowing no runs on five hits and three walks over 5.1 innings against the Giants. He struck out five.

EDGE Analysis

Jameson continued his strong start to his big-league career, as he did not allow a run for the second time in three starts. The rookie showed poise on the mound as the scoreless outing came despite being forced into the stretch in each of the six innings he appeared in. Jameson was hit hard in Triple-A to the tune of a 6.95 ERA through 114 innings this season, so he will be worth keeping an eye on to see if his breakout is for real.

Jameson (2-0) picked up the win in the second game of Tuesday's doubleheader split with the Dodgers, allowing two runs on seven hits and a walk over six innings. He struck out seven.

EDGE Analysis

After tossing seven shutout innings in his big-league debut last Thursday, Jameson delivered another quality start for Arizona in his encore. The 25-year-old righty tossed 62 of 94 pitches for strikes and extended his career-opening scoreless streak to 12.1 frames before Max Muncy touched him up for a two-run blast. Jameson had some issues keeping the ball in the park in the minors, but with two impressive outings out of the gate, he seems to be locking down a spot in the D-backs' Opening Day rotation in 2023.

Jameson is scheduled to start Tuesday in the second game of a doubleheader with the Dodgers in Los Angeles.

EDGE Analysis

The rookie right-hander is unsurprisingly getting a second turn through the rotation after he struck out five while holding the Padres scoreless over seven frames in his MLB debut last week. Prior to his call-up from Triple-A Reno, Jameson posted unremarkable numbers (6.95 ERA, 1.59 WHIP) over a larger sample of innings (114) in the hitter-friendly Pacific Coast League, so he won't make for the most comfortable streaming option in a road start against one of baseball's top offenses.

Jameson (1-0) earned the win over San Diego on Thursday, allowing two hits and one walk while striking out five batters over seven scoreless innings.

EDGE Analysis

Jameson has posted an uninspiring 6.95 ERA and 1.95 WHIP in 22 outings at the Triple-A level this season, but he looked like a seasoned major-leaguer in his Diamondbacks debut. The 25-year-old surrendered just two hits in the contest, keeping the Padres off the scoreboard for seven frames. Jameson wasn't overpowering -- he induced a modest eight swinging strikes -- but he allowed just two runners to reach second base and retired the final nine batters he faced. Given his strong start Thursday, he's likely to get another turn in the rotation next week.

Jameson was called up from Triple-A Reno and will start Thursday against the Padres.

EDGE Analysis

The 24-year-old was previously announced as the starter for Thursday's series opener, and he's now officially been added to the big-league roster. Jameson has a 6.95 ERA, 1.59 WHIP and 109:42 K:BB across 114 innings with Reno this year, and he'll have a tough matchup versus the Friars in his MLB debut.

The Diamondbacks will promote Jameson from Triple-A Reno to start Thursday's game against the Dodgers, Nick Piecoro of The Arizona Republic reports.

EDGE Analysis

The 25-year-old right-hander becomes the latest upper-level pitching prospect to get a trial in the big-league rotation after Tommy Henry and Ryne Nelson both received looks in the second half of the season. Henry has since been moved back to Reno, but Jameson will now receive a look as Arizona temporarily expands to a six-man rotation in a busy portion of the schedule. Though Jameson's numbers at Reno aren't impressive on the surface (6.95 ERA, 1.95 WHIP and 109:42 K:BB over 114 innings), he pitched primarily in hitter-friendly parks in the Pacific Coast League. He's at least done well to keep the free passes in check since the All-Star break (6.4 percent walk rate in 54.1 innings).