Diamondbacks Set for Important National League Matchup in St. Louis

The Arizona Diamondbacks (26-24) will face off against a shockingly potent St. Louis Cardinals (27-23) squad in the first matchup between the clubs of 2025. A three-game set between the two playoff hopefuls will kick off on Friday, May 23 at Busch Stadium in St. Louis.

Arizona has gone 13-11 on the road throughout 2025, just slightly above .500, whereas the Cardinals have been dominant at home, posting a 16-8 record.

The D-backs are coming off a hard-fought series loss to the Dodgers, now on a two-game skid. They have, however, won five of their last nine games and have won two of their last three series. St. Louis is likewise on a two-game skid entering this series after taking a series loss against the MLB-leading Tigers.

Standings

While both the Diamondbacks and Cardinals share nearly the same record, with St. Louis only one game ahead in the Wild Card standings, their divisional situations are far different. The Cardinals trail the Cubs by only three games for the NL Central.

On a Wild Card front, the Cardinals stand between Arizona and a potential playoff spot, holding only a one-game lead. This gives the D-backs a golden opportunity to leapfrog St. Louis with a series win. Still, both clubs sit on the outside looking in as the Padres and Giants currently hold Wild Card positions, trailing only the Mets, who stand with a record of 30-20.

The National League West continues to be a bloodbath, with four teams holding 26 wins or better. The Dodgers still headline the division with a record of 31-19, or five games ahead of the D-backs for the NL West crown.

Pitching Matchups

Friday, 5:15 p.m. MST

Zac Gallen, RHP: 3-5, 5.14 ERA, 4.68 FIP in 56 IP

Gallen's last outing came in disastrous fashion against the Rockies. There he allowed six earned runs in five innings of work against Colorado, surrendering four home runs on the day. The right-hander has struggled with consistency, looking dominant at times, but coming out floundering in other outings.

Miles Mikolas, RHP: 3-2, 3.77 ERA, 3.58 FIP in 45 IP

Mikolas has been on a dominant run of starts. In his last seven outings the 26-year-old righty has allowed no more than three runs, pitching to a 2.17 ERA over that span. Length has been a concern however, with him not going deeper than six innings in any start in 2025.

Saturday, 11:15 a.m. MST

Merrill Kelly, RHP: 5-2, 3.26 ERA, 3.46 FIP in 58 IP

Kelly has been on a hot stretch of starts, seemingly overcoming his cramping issues which plagued him earlier in 2025. He has allowed more than two runs only once since May 8th, and has posted five or more frames in each of those starts. In his career he is 3-1 with a 2.75 ERA against the Cardinals.

Matthew Liberatore, LHP: 3-3, 2.92 ERA, 2.29 FIP in 52.1 IP

25-year-old Liberatore has been one of the most dominant southpaws in all of baseball in 2025. He has posted a solid amount of innings while dominating hitters consistently. The lefty has posted fewer than six innings only twice this season, and is coming off a start where he allowed only one run in six innings against the Royals.

Sunday, 11: 15 a.m. MST

Brandon Pfaadt, RHP: 7-3, 3.81 ERA, 5.00 FIP in 56.2 IP

Pfaadt leads all MLB starters in pitching wins with seven on the year, but has only survived his last few outings. His peripherals indicate that he has been extremely lucky, despite allowing 13 runs in his last four starts, accounting for over half of his earned run total.

Sonny Gray, RHP: 5-1, 4.02 ERA, 3.79 FIP in 56 IP

Gray has been an ace for years, and was set to become a coveted piece at this year's trade deadline. Now that the Cardinals are back in contention, his ability to limit walks and strike batters out makes him a ferocious opponent. The D-backs have generally hit right-handers well, but they have a tough matchup ahead.

Who's Hot, Who's Not

Gabriel Moreno posted another big series, hitting his second and third home runs of the season. The 25-year-old backstop is hitting .421 over his last five games, with a 1.371 OPS over that time. Corbin Carroll struggled against the Dodgers, collecting only three hits in 12 at-bats against Los Angeles. He did, however, post a triple and a go-ahead home run in the series.

Ketel Marte also tallied three hits against the Dodgers, launching his seventh home run of the season in the series finale. The second baseman is batting .292 in his last six games, with two home runs in that time.

The Cardinals' Brendan Donovan currently leads the National League in hits and has settled in nicely into a second base role. He posted a three-hit game against the Tigers in the series opener between the clubs, but went hitless in the two games since.

Potential Roster Move

According to recent reports from Jody Jackson among others, manager Torey Lovullo stated following the Dodgers series that there "is a good chance" that Justin Martinez will join the Diamondbacks in St. Louis.

The D-backs have been missing their closer, and the results from the bullpen have reflected this loss. With Martinez and his triple digit fastball hopefully returning soon, the entire bullpen group will be significantly deeper.

Bullpens

Arizona's bullpen struggled against the Dodgers, with Ryan Thompson and Shelby Miller each having a big inning against them, leading to Los Angeles throwing runs on the board.

This is not an isolated event, as since co-closers Justin Martinez and A.J. Puk went on the injured list, the reliever staff has been among the worst in baseball. The Diamondbacks now rank 27th in baseball in reliever ERA at a 5.28 mark.

The Cardinals on the other hand rank 15th in baseball in bullpen ERA, and 6th in the National League. Closer Ryan Helsley, a name which the D-backs have coveted and even tried to acquire during the offseason, has been excellent. The flamethrowing righty has pitched to a 2.81 ERA in 16 innings, saving nine games.