NEW YORK -- The Padres' league-youngest rotation has been one of the season's biggest surprises through the first two months.

And reinforcements are on the way.

Dinelson Lamet is slated to begin a rehab assignment with Class A Advanced Lake Elsinore on Wednesday night. The hard-throwing right-hander hasn't pitched since he sustained an elbow injury on the final day of Spring Training 2018. He underwent Tommy John surgery that April.

There's still no timetable for Lamet's return. In all likelihood, he will likely need a lengthy rehab stint after missing the entire 2018 season. Generally, rehab stints last a maximum of 30 days for pitchers, but in the case of Tommy John surgery, three additional 10-day renewals are allowed.

"He'll move at his own pace," said manager Andy Green.

Lamet has spent the past few weeks throwing in extended spring training games at the team’s complex in Peoria, Ariz. He's reached three innings on multiple occasions, but the team expects only two innings from him on Wednesday against Rancho Cucamonga.

Lamet's presence would be a boon for a rotation that features several pitchers who will have their workloads restricted this season. Many have wondered how the Padres might combat innings limits on Chris Paddack and Matt Strahm -- their two best starters. Lamet's arrival could mitigate some of those concerns.

"If this rehab goes well and he's available at the end of June, that'd be huge for us," said Green. "He was our best starter, there was no question about that, coming into the 2018 season. Losing him on the last day of spring ... That was a tough loss for us last year."

In his 2017 rookie campaign, Lamet notched a 4.57 ERA and struck out 139 hitters in 114 1/3 innings -- the best strikeout rate for any rookie starter in Padres history. Lamet did so using an otherworldly slider and a high-octane fastball, though questions persist about his third pitch. In the past he's used a curveball and a changeup, but with much less success. He’s still throwing both.

At 26, Lamet would qualify as third oldest among the eight starters the Padres have used this season. Despite have the youngest rotation in the Majors, San Diego has jumped from 27th to seventh, with a 3.82 starters' ERA this season.

Other injury updates

• Outfielder Franchy Cordero is expected to begin a rehab assignment with Triple-A El Paso on Friday as he recovers from a stress reaction in his right elbow. The Padres dearly miss Cordero's left-handed bat as a platoon option in the outfield -- specifically in center.

Cordero has received more than 20 at-bats at extended spring, and Green noted that his progression to the big leagues might be quick. It depends, Green said, on how fast he regains his timing at the plate.

• Utility man Jose Pirela began his rehab assignment with El Paso on Wednesday. He's been out since April 21 with a strained left oblique.