OAKLAND -- Jesús Luzardo is quickly advancing toward his return to the A’s.

After completing a 51-pitch bullpen session on Sunday in Anaheim, the left-hander is now set to join Triple-A Las Vegas for a rehab start on Thursday against the Sacramento River Cats. Luzardo has been on the injured list since May 2 due to a fractured left hand.

“We’ll feel it out and see how things go here,” A’s manager Bob Melvin said. “He certainly needs at least one rehab assignment to get the game feel and adrenaline. We’ll see what we think after the first one and monitor what is going on here, as well.”

• 'Dumb mistake' gives Luzardo time to think

One option on the table for Luzardo would be for the A’s to bring him back after his first rehab start and stretch him out as a reliever. Not only would this expedite the 23-year-old's return, but it would also provide an electric arm in a bullpen that could use some help after getting hit around over the past week. Entering Monday’s game against Seattle, A’s relievers had posted an 8.63 ERA with four blown saves over the last eight games.

Luzardo, who spent time in Oakland's bullpen at the start of his big league career, holds a 3.32 ERA with 23 strikeouts across 21 2/3 innings in nine relief appearances.

“It would allow us to get him back sooner than later,” Melvin said. “If we were going to bring him back and want a full complement of pitches, he would probably need around three rehab starts. We’re still thinking about it some. We’ll just see how he feels after the first one.”

Jefferies makes 2021 debut at Triple-A

Just narrowly missing out on the final slot in the A’s rotation coming out of Spring Training, Daulton Jefferies -- Oakland’s No. 4 prospect, per MLB Pipeline -- was considered to be at the top of the list to get the call to the big leagues should the need for help in the rotation arise. But shortly after Opening Day, Jefferies was shut down with biceps tendinitis. Now, he has a chance to get back on that fast track.

Jefferies was activated from the Minor League injured list and is scheduled to start for Triple-A Las Vegas on Monday. This is his first game action since Spring Training, when he dazzled with a 1.50 ERA and 24 strikeouts against six walks in six Cactus League games.

“He’s had a rough go of it,” Melvin said. “It looked like he was hitting his stride and on the verge of making the big league team, and then the injury bug popped up. It’s always nice to have that kind of depth. It’s good to see. Hopefully, he moves along pretty quickly and pitches well to make us have to make a tough decision.”