"What you're going to find, if you play the outfield on a soggy field, the running on the field will slow down," he said. "It's almost like you're running on a beach, where you have to work harder. That's something we probably would want to stay away from."
Turns out Rivera would have gotten the day off anyway.
Monday's game between the Angels and the Kansas City Royals was postponed due to rain and will be made up as part of a doubleheader on Tuesday.
Scioscia made the decision to keep Rivera, who strained his right hamstring Sunday against Oakland, out of the lineup as light rain fell about three hours before the game. The rain picked up to a steady downpour about an hour later and the game was called around 8:40 p.m. -- more than 90 minutes after its scheduled start.
The teams discussed making up the game in early September, when the Angels return to Kansas City, but decided against it -- even with more storms forecast for Tuesday.
"I'm glad the games are scheduled tomorrow," Scioscia said. "Our August and September are already packed with two makeup dates with Oakland and New York from rainouts."
The Royals could probably use the break.
Kansas City entered Monday's game on a six-game losing streak and dropped a season-worst 17 games below .500 (37-54) after Sunday's 4-3 loss to Tampa Bay.
The Royals have struggled all season with hitting and have had problems with the rotation at times after a superb start. Now the bullpen is causing problems, too.
Closer Joakim Soria has been solid, earning saves in six straight games, 14 of 16 overall. The problem is the Royals can't get the ball to him.
The bullpen blew three straight leads in a weekend series against Tampa Bay, giving up the winning run in the eighth inning each time to complete the sweep. Kansas City's bullpen has allowed 19 earned runs over its last 18 innings after posting a 2.78 ERA the previous 18 games.
"We'll keep playing to the best of our ability until somebody comes to the forefront in the eighth inning," Royals manager Trey Hillman said.
The AL West-leading Angels are headed in the opposite direction.
Los Angeles has won six of seven and moved a season-high 14 games over .500 with Sunday's 11-6 win over Oakland. And they're doing it without Guerrero or Hunter.
Guerrero has been out since July 8 with a strained muscle behind his left knee and a lower hamstring strain. He has picked up his conditioning and played catch on Monday, though Scioscia said he will likely spend the rest of the season as the Angels' designated hitter when he returns.
Hunter, who went on the DL the same day as Guerrero with an adductor strain, is a bit further from his return. The centerfielder is still limited to riding a bike and walking, and spent a half hour walking around the warning track in Oakland before Sunday's game.
"After three weeks (on the DL), they will be evaluated when we get back to Southern California," Scioscia said. "There are still some hurdles at the end they have to get over, but they are feeling better."