There are probably few teams in MLB as happy to see the calendar flip to August as the Seattle Mariners.

The troubling trend developing for the Seattle Mariners

July spiraled into a bad month for the M’s. They fell out of first place in the American League West for the first time in over two months, lost 10 of their final 15 games following a 5-4 start, went 1-7 in one-run contests and lost two series to the lowly Los Angeles Angels, including being swept for the first time all season.

On top of it all, star center fielder Julio Rodríguez and shortstop J.P. Crawford went on the injured list.

However, the Mariners added reinforcements at the trade deadline and enter August in a virtual tie for first place in the AL West with the Houston Astros, and they get strong challenge right away. The Mariners open the month Friday with a three-game home series against the NL East-leading Philadelphia Phillies, who come in with the second-best record in MLB at 65-43.

Here’s three things to know as Seattle begins a two-month dash for the AL West title against one baseball’s top squads:

Baseball’s best top staffs square off

The Mariners and Phillies have been considered to be the best in baseball this season. The numbers back it up.

Both rotations rank in the top five in the league fWAR, ERA, FIP, opponents’ batting average, WHIP, walks per nine innings, home runs per nine innings, innings pitched and quality starts. Here’s where they stand:

• fWAR: 1. Phillies (12.7), 2. Mariners (11.9)

• ERA: 1. Mariners (3.30), 2. Phillies (3.31)

• OBA: 1. Mariners (.222), 2. Phillies (.227)

• FIP: 1. Mariners (3.54), 4. Phillies (3.63)

• BB/9: 1. Mariners (1.81), 5. Phillies (2.47)

• HR/9: 4. Phillies (0.98), 5. M’s (1.03)

• IP: 1. Mariners (640 2/3), 2. Phillies (626)

• QS: 1. Mariners (66), 2. Phillies (58)

• WHIP: 1. Mariners (1.04), 2. Phillies (1.12)

It would appear as if a pitching clinic is in line at T-Mobile Park this weekend, but neither team will seeing the best of the other’s rotation.

Philadelphia is dealing with multiple injuries. Former Mariner Taijuan Walker went on the IL with a right index finger strain in late June. Veteran right-hander Spencer Turnbull, who was moved to the bullpen in May due to Philadelphia’s wealth of starters, suffered a right lat strain in his first start after replacing Walker in the starting rotation. And All-Star left-hander Ranger Suárez recently went hit the IL with lower back soreness.

Former All-Star Aaron Nola and left-hander Cristopher Sánchez also aren’t scheduled to pitch for the Phillies.

The Mariners’ staff remains at full strength, but Luis Castillo and George Kirby won’t be taking the mound.

There’s still some good pitching matchups in store starting with Friday’s matchup between Bryan Woo (4-1, 2.35) and Tyler Phillips (3-0, 1.80). Phillips has made just three starts, but is coming off a four-hit shutout against Cleveland.

The marquee billing is Sunday’s series finale, as All-Stars Logan Gilbert (6-7, 3.11) and Zack Wheeler (10-5, 2.94) square off.

Seattle Mariners limping into August

The previously mentioned injuries to Rodríguez and Crawford are painful, but those aren’t the only health issues the Mariners are dealing with.

Breakout outfielder Víctor Robles left Tuesday’s game and didn’t play the following day with a lingering hip issue. Manager Scott Servais’ update after Wednesday’s game in Boston wasn’t very encouraging.

“I wish it was easy as just a couple days downs and it’ll going away,” Servais said. “I think this is something that he’s going to have to deal with here going forward. And then we’ll see. We’ll see how he feels.”

Robles has been red-hot since joining the team as a waiver pickup and currently helping fill the void in center field without Rodríguez. In 33 games with Seattle, Robles is slashing .360/.422/.520 eight extra-base hits and nine stolen base .

Seattle’s bullpen is also facing uncertainty after hard-throwing reliever Gregory Santos exited the game with a bicep issues. Santos was set to undergo an MRI when the team return to Seattle on Thursday. An update on Santos’ status will likely come Friday.

The good news is the Mariners are hopeful Rodríguez, who went on the IL with a high right ankle sprain on July 23, will return at some point during the homestand. Outfielder Dom Canzone also began a rehab assignment with Triple-A Tacoma on Thursday.

The bad news is Crawford likely won’t return until September due to a fractured pinky.

Mirroring slide

The Mariners’ tough month of July was detailed a bit earlier. It also didn’t go much better for the Phillies. Philadelphia produced an identical 10-14 record, went 1-5 in one-run games and closed the month with a 3-9 stretch after the All-Star break.

The short-handed rotation played a factor in the Phillies’ struggles, with their starters falling to the middle pack in most categories and ranking 20th in ERA (4.64) in July after being near or at the top of the leaderboard all season. Phillies relievers also struggled with a 6.17 ERA and 19 home runs allowed over 84 2/3 innings.

In an effort to alleviate the bullpen problems, they acquired standout Angels closer Carlos Estévez and White Sox left-hander Tanner Banks at the trade deadline.

The Mariners could be catching the Phillies at the right time, but Philadelphia could say the same about the banged-up Mariners.

More on Seattle Mariners and the trade deadline

• How experts are grading Seattle Mariners trade deadline moves
• Mariners Trade Deadline Tracker: Keep up on every move
• Mariners’ Dipoto on top prospects staying put at deadline
• Drayer: Mariners navigated thin market for deadline adds
• A closer look at Mariners trade acquisition Justin Turner

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