WASHINGTON -- When manager Ozzie Guillen examined this season’s schedule in spring training, he assumed this weekend’s series between the Marlins and Nationals would be a pivotal showdown for National League East supremacy.

“I thought this series was going to mean a lot for both teams,” Guillen said. “I really did. I thought we were going to be fighting all the way to the end. It wasn’t that way.”

Not even close.

While the Marlins sit in dead last, the first-place Nationals are closing in on a playoff berth with a relatively comfortable lead on the Atlanta Braves.

“We are two different ballclubs,” Guillen said. “I think you get what you deserve, and the way we played, we don’t deserve to be in the pennant race. And the way they played, they should be there.”

Constant changes

The Marlins rolled out their 104th different lineup Friday, putting them within range of the franchise record.

The 1999 Marlins used 121 different lineups (excluding pitchers).

“To be honest with you, I’m kind of surprised it’s not more after all of the trades that we made,” said Marlins bench coach Joey Cora, whose job it is to write out the lineups given to him by Guillen.

The Marlins have only 23 games remaining, so matching the club mark won’t be easy. But they should make a run at the runner-up spot, the 2006 team’s 117 unique lineups.

Cora said three primary factors determine how often a lineup is changed: injuries, an individual slump and a team slump. Trades also figure greatly, and the Marlins dealt three of their Opening Day infielders in July.

“Ideally, you don’t make that many changes,” Cora said.

Johnson weighs in

Josh Johnson said he felt much more fatigued during his first season back from Tommy John surgery and not his second. Even so, Johnson said he thinks the Nationals are doing the right thing by shutting down Stephen Strasburg after his next start.

“They’re playing it smart,” Johnson said.

Like Strasburg, Johnson underwent elbow ligament replacement surgery in the month of August and was back on a major-league mound the following season.

But Johnson was able to get back a bit sooner and made 14 starts in his comeback season with the Marlins as opposed to just five for Strasburg when he made it back at the end of last year.

Johnson followed that abbreviated campaign with a full slate in 2009, making 33 starts and totaling 209 innings. Strasburg will end up making 29 starts and throwing about 170 innings before the Nationals put him away for good. Still, despite the heavier workload, Johnson said he felt more tired after 2008 than he did at the end of ’09.

“I was probably more tired [the first year] back just because of all the bullpens,” Johnson said. “It felt like I threw 50 bullpens. It was probably more like 25, which is a whole lot, but that’s not even counting simulation games and live batting practice.”

Coming up

•  Saturday: Marlins LHP Mark Buehrle (12-12, 3.73 ERA) at Washington Nationals LHP Ross Detwiler (9-6, 3.15), 1:05 p.m., Nationals Park.

•  Sunday: Marlins RHP Ricky Nolasco (11-12, 4.64) at Nationals RHP Edwin Jackson (9-9, 3.63), 1:35 p.m., Nationals Park.

•  Scouting report: Because the Marlins have implemented a six-man rotation, Buehrle will have a difficult time reaching 200 innings pitched for the 12th consecutive season.

Buehrle needs to total at least 26 1/3 innings over his final four starts to extend the streak.