Wilson Ramos of the  Mets warms up on the field during...

Wilson Ramos of the  Mets warms up on the field during summer camp at Citi Field on July 14. Credit: Jim McIsaac

All of a sudden, the Mets’ catching situation is in a state of significant flux.

Wilson Ramos was out of the lineup Sunday for a second day in a row because he was “dealing with a personal matter,” manager Luis Rojas said. He declined to provide further information, in line with the Mets’ recently implemented policy not to comment on players who are absent.

Also Sunday, the Mets added Rene Rivera to the 40-man roster. That gives them four available catchers, including Tomas Nido, who got the start in an exhibition against the Yankees on Saturday, and Ali Sanchez, who finished last year with Triple-A Syracuse.

Rivera went 0-for-2 in the Mets’ 6-0 exhibition loss to the Yankees on Sunday.

“One of the things you want to do in a season like this, and having the luxury of a 30-man roster to start the season, you can have depth in different positions,” Rojas said. “Rene is a guy that has experience and can definitely help us this season to achieve our goals.”

It is not clear what Rivera’s addition to the 40-man roster means for the other catchers, but among the possibilities are the Mets plan to carry three of them — Ramos, Nido and Rivera — to start the season. Alternatively, Rivera provides an extra degree of depth in case Ramos cannot play Opening Day.

Rivera being on the 40-man roster means the Mets have to put him on the active roster — which starts with 30 players before decreasing to 28 and then 26 over the first month — or risk losing him to another team.

With Opening Day five days away, Rojas said “we’re not there yet” regarding roster decisions.

“A lot of strategy is in consideration as far as our 30-man to start the season,” Rojas said. “That definitely could be one of those strategies, you know carrying three catchers, but we're not there as far as how many catchers we're going to carry. How many outfielders, infielders and pitchers as well.”

Rivera played for the Mets 2016-17 and part of 2019, stints during which he became known as Noah Syndergaard’s preferred backstop. Syndergaard won’t pitch this season due to Tommy John surgery, but Rivera is reputed to be a strong defensive catcher with good rapport with pitchers generally, a skill set desired by most any club.

In parts of 11 seasons with eight teams, Rivera is a career .221 hitter with a .272 OBP and .354 slugging percentage. He trimmed down significantly over the offseason — he said he lost about 30 pounds and is listed now at 215 — and seemed even skinnier when camp restarted early this month.

Nido spent most of last season as Ramos’ backup, and he along with Rivera would be in line for much more playing time if Ramos is out.

The question with Nido: Can he improve as a hitter? Like Rivera, he is a defense-first catcher who offers little at the plate. He had a .191/.231/.316 slash line in 50 games in 2019, which was marginally better than his career numbers.

Rojas said he believes Nido can be better. He was Nido’s manager in 2016, when he won the Florida State League batting title for advanced Class A St. Lucie, hitting .320 (with an .816 OPS).

“I know that if he maintains his focus and he’s able to be consistent at the plate, he can definitely be a good hitter,” Rojas said. “It hasn’t translated yet to the big league level, but … I know that’s something we can definitely get from him when he gets his chances to play.“Nido worked really hard before getting into camp the first time on his offense. He’s always been a good defensive catcher. There’s some things that he definitely some things he needs to tone down and work on [at the plate] as far as being more consistent.”