The Mets’ cleanup hitter and starting first baseman Sunday was Eric Wagaman, whom they had designated for assignment last month.

It was yet another reminder of the difficulties of this season, particularly at a position that the Mets had not worried about for the previous seven years.

Their primary replacement for Pete Alonso, Jorge Polanco, has played 14 games and on Friday began his second attempt at a rehab assignment that he feels more confident about than the first.

After lasting just six minor league games in late May and early June before his ankle soreness became too intolerable to continue, Polanco again played with Triple-A Syracuse on Friday and logged three at-bats (0-for-3 with a strikeout) in another first step — and it is just a first, with a return not imminent — he believes went well.

“I think I’ll be able to return because my leg just feels stronger,” Polanco said through interpreter Alan Suriel from Citi Field on Sunday before the Mets and Phillies finished a series. “I’ve put more of a workload in there. But I’ve also been able to recover properly.”

Polanco originally landed on the injured list in mid-April with a right wrist contusion, an issue he says is fully behind him. But he also had been bothered by Achilles bursitis in his right ankle, which has not gone away and which he and the Mets believe will not go away this season.

“There’s still pain there, but it’s a pain that I feel like I can tolerate,” said Polanco, a 13-year veteran who has dealt with myriad injuries. “I’m in a position right now where my ankle does feel good enough to go out there and play.”

The next step is to begin logging games and at-bats, if not defensive appearances for a player who likely will solely serve as a designated hitter whenever he is ready. Interim manager Andy Green said there is no firm timeline for Polanco to return, as the club needs to see how his ankle responds.

Polanco, who was signed to a two-year, $40 million pact, acknowledged his own situation and his team’s “doesn’t feel good.”

“The expectations were high. The team as a whole has not played up to our capabilities,” Polanco said. “Also, no one wants to be injured. From that aspect, it hasn’t been a good feeling.

“But at the same time, you have to go out and continue to be positive and try to turn the tide.”