Gerrit Cole is starting to feel the itch as he continues to build his rehab workload.

The Yankees ace took his latest step Saturday, throwing a 40-pitch bullpen session that was the equivalent of two innings after his first four sessions involved just one.

Cole threw 20 pitches, sat for a few minutes and then threw 20 more, with Oswaldo Cabrera and Jahmai Jones standing in without swinging.

Assuming he recovers well from Saturday, Cole’s next step could be facing hitters in live batting practice for the first time since he was shut down in March with elbow nerve inflammation and edema.

“That’s certainly a possibility early next week,” Cole told The Post before the Yankees’ 6-1 win over the White Sox on Saturday at the Stadium.

The reigning AL Cy Young winner did not want to get too far ahead of himself — he still has a ways to go and more boxes to check off before he could return by late June or early July — but his excitement about his progress and how he has been feeling physically was evident.

“Today was a really good day,” Cole said. “Today was a lot of fun. Got a couple stand-ins in. Was able to bump the [velocity] a little bit.”

After a session in which his fastball velocity sat in the low 90s and he threw all his pitches, Cole indicated things were beginning to feel more real as he ups his workload.

“It’s starting to come,” he said.

Pitching coach Matt Blake said he can sense Cole starting to champ at the bit.

“I think that’s a big one for him, to check that box,” Blake said. “Each one, he’s gaining confidence in that the arm’s bouncing back and the stuff’s been sharp. For where he is in the progression, I think we all feel pretty good about it.”

Blake said the next step would either be facing hitters or repeating the two-up bullpen session, depending on how Cole bounces back from Saturday.

Once Cole advances to live batting practice sessions, he would need a handful of those before going out on a rehab assignment.

“[He’s] probably a step ahead of where he was when he came into camp this year, which is encouraging,” Blake said. “Probably one notch ahead of a typical spring training progression.”

Spring training is six weeks, so based on where Cole is in his progression, he might need around or slightly less than that to be ready to come back.

Once he begins a rehab assignment, that will start a 30-day clock.

But the Yankees plan to take their time with Cole, as they have erred on the side of caution throughout this entire process to make sure they get the best, healthiest version of him when he returns.

It doesn’t hurt that the rotation has been a strength even without Cole to start the season, entering Saturday with a 3.03 ERA through 46 starts, good for the third-lowest mark in the majors.