PHOENIX -- The Mariners' rotation is nearing a return to full strength as the club continues its push for the postseason.
Mike Leake (Spike), who was scratched on Tuesday with an illness, is scheduled to make his return on Sunday against the D-backs at Chase Field. James Paxton (Big Maple), who is on the 10-day disabled list with a left forearm contusion, threw a bullpen session on Friday and could return during Seattle's series in Oakland from Aug. 30-Sept. 2.
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Leake's last start was skipped when he was scratched an hour before his scheduled start against the Astros on Tuesday. The right-hander will be making his first start since Aug. 15, when he threw eight scoreless innings against the A's.
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"Talking to Mike a little bit [Thursday], he's feeling a little bit better, thought Sunday would be the right time to insert him back in there," Mariners manager Scott Servais said. "He should be getting his legs underneath him and stuff."
Paxton has been on the disabled list since Aug. 15. The left-hander's bullpen session prior to Friday's series opener vs. the D-backs at Chase Field was his first since he sustained the injury. He was expected to throw all of his pitches during the session.

Servais said Paxton likely won't return to the rotation until the series against the A's, because he doesn't want Paxton to hit in a National League ballpark. The Mariners play at Arizona through Sunday, then head to San Diego for a two-game series starting Tuesday.
"It'd probably be better just to keep him in the American League," Servais said. "There's a lot of things that can happen, and we want James to focus on pitching."
Paxton and Leake have been Seattle's most reliable starters this season. Paxton is 10-5 with a rotation-best 3.68 ERA in 24 starts, while Leake is 8-7 with a 3.90 ERA in 25 starts.
Detwiler, Vincej clear waivers
Left-hander Ross Detwiler and infielder Zach Vincej both cleared waivers on Friday and were outrighted to Triple-A Tacoma.
Vincej was designated for assignment on Tuesday. He played one game with the Mariners during a brief stint with the club from July 30-Aug. 1. He went 2-for-4 with an RBI against the Astros on Aug. 1.
Detwiler was designated for assignment on Wednesday. The lefty made his Seattle debut when he threw six innings of relief against the Astros on Tuesday, allowing three runs on eight hits with two strikeouts and two walks.
Worth noting
• After exiting Wednesday's game with tightness in his rib cage, Jean Segura (El Mambo) was back in the lineup for Friday's opener in Arizona. Segura, who was traded from the D-backs to the Mariners in November 2016, started at shortstop and batted third.
• Nelson Cruz (Boomstick) was out of the lineup on Friday, and that will likely be the case for the entire three-game series in Arizona and two-game set in San Diego, where there is no designated hitter. Cruz has only started at DH this season after starting five games in right field in 2017.