Washington catcher Wilson Ramos is tended to after hurting his right knee landing awkwardly following a leap to snare a high relay throw in the sixth inning on Monday night against Arizona. (Andrew Harnik/Associated Press)

A month or so ago, the Washington Nationals expected to see Stephen Strasburg pitching to Wilson Ramos in the National League Division Series, two weapons they always thought they would build around finally performing the way they thought they could. Now they will have neither.

Ramos tore the anterior cruciate ligament in his right knee Monday night, Nationals Manager Dusty Baker confirmed Tuesday. Strasburg will almost certainly be unavailable for the NLDS, Nationals General Manager Mike Rizzo confirmed not long after.

Ramos has no chance to return this season, no matter how far the Nationals go. Whether Strasburg could return for the National League Championship Series — or, perhaps, the World Series — remains unclear.

“I haven’t seen him after his throwing program [Tuesday], but just the calendar, it’s unlikely that he’d contribute in that first series,” said Rizzo, who added that Strasburg threw from 90 feet Tuesday, which is farther than he had thrown before.

But Strasburg hasn’t thrown off a mound since exiting with his elbow injury in the third inning against the Braves on Sept. 7, and Rizzo’s statement is the closest the Nationals have come to declaring the 28-year-old Strasburg out for the NLDS, which begins Oct. 7.

Ramos, meanwhile, will need surgery and will be seeing doctors this week to determine when he will have it. His season is over, and because ACL injuries generally take six to nine months of rehabilitation in the best scenarios, he may not be ready for spring training or the start of next season, either.

“I just talked to him a few minutes ago. He’s upbeat about things,” Baker said. “He knows that other guys have come back from this. I told him about Adrian Peterson [of the NFL’s Minnesota Vikings, who came back from ACL surgery in nine months in 2012]. He didn’t really know who I was talking about. At least he doesn’t have to run through the line and stuff.”

Ramos tore the same ACL in May of 2012, and it cost him the rest of the season. This one may cost him more than playing time, because the 29-year-old will be a free agent after this season and turned down an offer of three years and $30 million from the Nationals in the last month.

Those familiar with the market considered that offer low, particularly considering Ramos upped his batting average by 80 points from last season, to .307, 10th in the NL as of Tuesday. His .850 on-base-plus-slugging percentage is more than 70 points higher than any he compiled previously. His 22 home runs, 25 doubles, 80 RBI and 148 hits are all career highs.

The Nationals now turn to Jose Lobaton and rookie Pedro Severino to catch for them in the playoffs. Both are better defensive players than Ramos. Lobaton is known for his ability to frame pitches. Severino is the Nationals’ top catching prospect because of his glove, not his bat.

Neither Baker nor Rizzo would commit to Lobaton as the everyday starter now, in part because his injured right ankle bothers him more when hitting right-handed. Rizzo indicated the Nationals might match up over the last week of the season, in which case Severino would likely play against lefties, Lobaton against righties. Lobaton has 17 plate appearances against left-handed pitchers this season.

“All of our catchers are very good catchers. It’s just that he is not only the top offensive catcher on our team, a big part of our offense, he’s one of the top offensive catchers in baseball,” Baker said. “We’ll really miss his offense. I think Loby and Severino can replace [him] on defense, but it’s up to some of the other guys to offset his loss on the offensive side of the ball.”