The benefit is already apparent.
Adam Jones hit a pair of two-run homers and the Orioles received another steady performance from right-hander Chris Tillman in a 7-2 victory over the Boston Red Sox on Saturday night.
Jones was coming off two straight days off and Tillman was pitching with an extra day of rest. Not only that, but Showalter rested Steve Pearce and Nick Markakis, who probably would have played if the games were particularly meaningful.
Pearce got a cortisone shot in his ailing right wrist and Markakis sat out with a sore shoulder. On Friday, shortstop J.J. Hardy (back spasms) was rested.
"One of the good things about being able to know you're in early is things like Nick," Showalter said. "During the season we probably would have pushed it. Same thing with Stevie, J.J. We gave Adam a couple days (off)."
The victory moved the Orioles within two games of the Angels in the race for home-field advantage throughout the playoffs, pending Los Angeles' late game against Texas.
"We still have something to prove," Jones said. "We're trying to catch Anaheim for the best record overall. Guys understand that. Just because the normal stars aren't playing doesn't mean that the guys that are playing can't easily fill in the role. That's what the guys are doing. It's a collective team."
But the object now is to be fresh and ready for the postseason.
"It's tough, but we've got to be smart and I've been cutting down on my swings a lot," Pearce said. "It's just that time of year."
Tillman (13-5) gave up two runs and five hits in seven innings. He has allowed three runs or fewer in 20 consecutive starts, tied with Steve Barber for the second-longest such run in Orioles history behind Dave McNally (25).
"He was getting better as the game went on," Showalter said. "Maybe in 10 or 11 days, two weeks or whatever it is, he continues to pitch in that game."
Baltimore's likely starter in Game 1 of the playoffs, Tillman is 6-0 in 13 starts since July 12.
Jones connected against Rubby De La Rosa (4-8) in the third inning and Heath Hembree in the fifth. It was his sixth career two-homer game, the second this season.
Christian Walker also went deep for Baltimore, hitting a solo shot in the fourth for his first major league homer.
Boston got another home run from David Ortiz, his third in two games and No. 35 of the season. Ortiz now has 466 for his career, passing Dave Winfield for sole possession of 33rd place on the all-time list.
De La Rosa gave up four runs in four innings and is winless in his last seven starts.
"He's still showing good velocity," manager John Farrell said. "Just the consistency to the overall execution is what's missing right now."
After Mookie Betts walked to open the game, Ortiz hit a 75 mph curveball into the seats in left-center. He was previously 2 for 24 against Tillman with no home runs.
"We didn't really do anything after that," Farrell said.
Jones tied it in the third with Baltimore's major league-leading 200th home run of the season. The Orioles have hit at least 200 in three straight years for the first time in franchise history.
Inserted as a late replacement for Pearce, Walker led off the fourth with a drive into the center-field bleachers. The Orioles' fourth-round pick in 2012 was playing in his third big league game.
The Orioles wrap up their regular-season home slate when they send Miguel Gonzalez (9-8, 3.28 ERA) to the mound on Sunday against RHP Joe Kelly (2-2, 4.21 ERA) , who makes his ninth start for Boston since being traded from St. Louis on July 31.
COUNT THE INNINGS
Red Sox: De La Rosa has pitched exactly four innings in each of his last three starts. He needed 80 pitches to get through four in this one.
Orioles: Tillman passed the 200-inning mark for the second straight year.
"Two hundred is important because it means you're out there and competing for your team, and you're giving your chance a team to win," he said.