Wilson Ramos will become a free agent this winter. (Alex Brandon/Associated Press)

Early last month, catcher Wilson Ramos, a free agent this winter, said he was waiting on the Nationals to offer him a contract beyond this season. He was playing the best baseball of his life, and he said he wanted to stay in Washington.

A proposal arrived soon after. The Nationals offered Ramos a three-year contract worth a little more than $30 million last month, according to people with knowledge of the situation. Ramos declined it. He is intent on entering the free-agent market, where he is expected to garner richer offers as one of the top players available. Today’s Knuckleball first reported the offer.

Until last month, Ramos was the best offensive catcher in baseball this season and helped carry the Nationals’ offense alongside Daniel Murphy. The Venezuelan made his first all-star team and was batting .336 with a .933 on-base-plus-slugging percentage on Aug. 10, his 29th birthday. He had already clubbed a career-high 18 home runs. The production was an extreme outlier for a player who had never hit better than .272 or posted an OPS higher than .779 over the course of a full season. Ramos credited the eye surgery that corrected his vision, a better offseason workout regimen and staying healthy for the unexpected surge.

Then his production plummeted. Over the next month, Ramos hit .172 with a .478 OPS in 24 games (23 starts). He has since warmed up, with a hit in seven of his past eight games, but his batting average has tumbled to .303. His OPS is down to .843. Both are still career bests.

On Sept. 14, after hitting the go-ahead home run in a 1-0 win over the Mets, Ramos acknowledged that his looming free agency had become a distraction.

“The truth is I was thinking a lot at the plate,” Ramos said after the game. “I think I got distracted a little thinking about the contract and free agency. I talked to my wife a lot and relaxed at home. Now I’m more relaxed at the plate, only thinking about doing my job like I was doing at the beginning of the season.”

The Nationals didn’t expect Ramos to hit .330 all season, and the slump shouldn’t hurt his free-agent stock much. Unless the Texas Rangers unexpectedly decide not to exercise the bargain $5.25 million club option on Jonathan Lucroy’s contract for next season, Ramos and the Baltimore Orioles’ Matt Wieters will be the top catchers available in free agency. Ramos should get a significant raise on his $5.35 million salary this season, which ranks ninth highest among catchers.

Pittsburgh Pirates catcher Francisco Cervelli, who is making $3.5 million this season, removed himself from the bidding wars by signing a three-year extension in May worth $31 million — about what the Nationals offered Ramos. Cervelli will make $9 million next season, $10.5 million in 2018 and $11.5 million in 2019. Cervelli is considered a top-notch defender but is a year older than Ramos, has had his own extensive injury history and has been suspended for using performance-enhancing drugs, and his offensive peak doesn’t approach the production Ramos sustained for most of this season.

The qualifying offer, however, could suppress Ramos’s earning power. If the Nationals make him the one-year offer, which is expected to climb to $16.7 million this winter, within five days of the World Series’s conclusion, Ramos would have seven days to decide whether to accept it. If he does, he’ll play next season for $16.7 million and become a free agent the following winter. If he rejects it, the Nationals would receive a compensatory pick between the first and second rounds of next June’s draft, and the team that ends up signing Ramos would lose a draft pick. If that team’s first-round pick is in the top 10, the team would forfeit its next-highest selection. If the team’s first-round pick is outside the top 10, then that team loses its first-round pick.

Last November, three players became the first to accept the qualifying offer. Wieters, 30, was one of them. Ian Desmond didn’t accept the offer from the Nationals and ended up signing a one-year, $8 million deal with the Texas Rangers in late February.

Of course, Washington and Ramos have time to agree on a long-term deal. If they don’t, the Nationals have Pedro Severino and Jose Lobaton as in-house options to replace Ramos. The free-agent or trade market could also produce the replacement.