BALTIMORE -- The Padres' rotation could get an important boost before the All-Star break.

Right-hander Dinelson Lamet is slated for another rehab start in his return from April 2018 Tommy John surgery. It will take place this weekend, potentially Friday.

If all goes well, the Padres will hold "a serious conversation" about reinstating Lamet into the rotation, manager Andy Green said.

"We'll give him one more [start] and evaluate where he is after that one," Green said. "He's getting closer and closer, and we're getting more and more excited about that concept."

Lamet hasn't pitched since the final day of the 2018 Cactus League season, when he tore the ulnar collateral ligament in his right elbow. In five rehab starts this year, he has a 6.16 ERA.

But after some early struggles, Lamet appears to have regained the dominant form he showcased during his rookie campaign in 2017. On Saturday with Triple-A El Paso, Lamet worked five innings of two-hit ball, striking out eight.

Lamet hasn't thrown more than 73 pitches in any rehab start, and it's unlikely he goes much higher than that number in his next time out. Upon his return, the Padres plan to limit Lamet’s pitch count, and they'll give him an extra day between outings -- like they've done all season with Matt Strahm and Chris Paddack, who have yet to pitch on four days' rest.

In 21 starts in 2017, Lamet posted a 4.57 ERA with 139 strikeouts in 114 1/3 innings -- the highest K/9 ratio of any starter in Padres history with at least 50 innings in a season.

If the Padres plan to keep Cal Quantrill in their bullpen, they'll need at least one more starting pitcher for their stretch of 10 games in 10 days to end the first half of the season.

If all goes well in his final rehab start, it's reasonable to expect Lamet back for the Padres' four-game series against the Dodgers to close the first half. His start could line up for that series opener on July 4.

Noteworthy
• Jose Castillo has yet to throw off a mound since he suffered a setback with the flexor strain in his left forearm. The lefty reliever is likely to throw a bullpen session in the next two or three days.

Castillo has missed the entire season after originally sustaining the injury during Spring Training. He was closing in on the end of his rehab assignment when the injury flared up again 10 days ago.

"He has not gone back to square one," Green said. "But he's not at a point where he's toed the rubber, even in a bullpen setting. In the next couple days we expect that to happen. Then we'll have a better idea of what the next step looks like."