NEW YORK – Whether the Cubs ever get this leadoff-hitter thing right this season, their last, best chance might come Sunday when they get Ben Zobrist back from personal leave and Albert Almora Jr. back from the minors when rosters expand for the final month.

“When Zo comes back I anticipate giving him a couple shots up there,” manager Joe Maddon said, “but he’s not going to play every day, either. So that’s part of the concern.”

The Cubs’ have the worst leadoff on-base percentage in the majors (.284 entering play Thursday).

And even elevating Jason Heyward and his .355 OBP (at the time) into that spot didn’t do much for the numbers, except drop them.

Heyward agreed to the move to try to help the lineup’s soft spot, on the condition Maddon have enough patience to let him try to get comfortable there.

That extended through a rough month for Heyward, in large part for lack of a stronger everyday option.

In 30 starts leading off, he has hit just .158 with a .257 OBP after four hitless at-bats Thursday.

“More than anything, he just needs a little rest,” Maddon said. “I know the numbers aren’t there, but I love his presence at the top of the batting order. He still has a tendency to get a big hit when we need it.”

Defying the stats, the Cubs improved to 21-9 when Heyward leads off.

“I’ll tell you: presence matters,” Maddon said.

Maddon said if Almora is back to hitting lefties well when he returns, he could be part of a mix-and-match solution (which worked well last year), and that Heyward will still get some starts there down the stretch.

“I’m not as worried about this as maybe some other people would be worried,” said Maddon, who was informed that Twitter appears to be sweating profusely over the issue.

“They are?” he said. “I didn’t take that pandering-to-Twitter class.”

Contreras in a week?

Catcher Willson Contreras, who hasn’t played since injuring his right hamstring Aug. 3, left New York Thursday to join Class AAA Iowa for a minor-league rehab assignment.

He’s expected to catch a few innings Friday to start a tightly monitored assignment that is expected to include rest days and at-bats as the DH.

“It’s probably going to be around a week or so,” Maddon said. “The [medical staff] really feels good about his strength level [in the leg]. That’s the important thing. After that it’s just creating timing at the plate.”

It could put him back in the Cubs’ lineup sometime during their series in Milwaukee Sept. 5-8.

Rizzo progressing but return not imminent

First baseman Anthony Rizzo missed a fourth consecutive game since his back locked up during Saturday’s game, and Maddon said he doesn’t expect Rizzo back for Friday’s series opener against the Brewers.

“He looked better walking around today, but I don’t have any specific day for him,” said Maddon, who had Ian Happ and Victor Caratini filling in for Rizzo in recent days.

Caratini homered twice off Mets ace Jacob deGrom Thursday.