Colorado (51-60) dealt Jimenez to Cleveland on Saturday, and Rogers (4-1, 7.31 ERA) was a good friend of the club's former ace. Now Rogers will move back into the rotation for his first start since April 25.
"I feel really good," Rogers told the Rockies' official website. "All I'm thinking about is that, whether it's out of the bullpen or in the rotation, I'm going to be ready. My arm and my body are feeling really good."
The right-hander went 3-1 with a 6.33 ERA in four starts in April and made one relief appearance in May before he was placed on the 15-day disabled list with a strained right lat muscle.
He has returned to pitch twice out of the bullpen, including a win Saturday when he entered in the second inning after Jimenez was pulled upon learning he was traded. Rogers allowed one run and one hit in five innings of a 10-6 victory at San Diego.
"The message is more of seeing the consistency, which we saw Saturday night, instead of vacillating with the up and down we've been dealing with," manager Jim Tracy said. "When you're talking about being part of a five-man rotation, obviously, that type of consistency from a momentum standpoint is imperative."
Rogers' only appearance against the Nationals came in relief, allowing one run over two innings May 13, 2010, in a 14-6 loss.
The Rockies are seeking to avoid their first five-game home skid in a single season since May 13-27, 2009. They were swept in a three-game set by Philadelphia following Wednesday's 8-6 loss.
"I think the frustrating part is coming out of spring training, we thought we had a really good ballclub and (we) just haven't played up to our potential for whatever reason," said Todd Helton, who homered and drove in three runs.
Washington (53-57) is beginning a 10-game trip after its four-game win streak was snapped Wednesday in a 6-4 loss to Atlanta.
Ryan Zimmerman comes to town on a 12-game hitting streak during which he's batting .423. He's a career .336 hitter against the Rockies, going 3 for 11 as Washington dropped two of three at home July 8-10.
Each team scored only five runs in that series. Helton went 5 for 11 with a homer and two RBIs.
Ross Detwiler (1-0, 2.35) threw two scoreless innings of relief in that series and now will start against the Rockies for the first time since a loss in 2009.
Detwiler is taking the rotation spot of Tom Gorzelanny, demoted to the bullpen.
"If we were fighting for a pennant, we might not do it," manager Davey Johnson told the Nationals' official website. "But since we're where we're at, it's time to start looking at some young arms."
The 25-year-old left-hander is 3-9 with a 5.08 ERA in 20 starts, including a win in his only one this year July 5 in his season debut. He gave up two runs in 5 1-3 innings of a 3-2 victory over the Cubs.
The Rockies are 17-14 against left-handed starters this year.