SAN DIEGO -- Santiago Casilla and Sergio Romo have exchanged roles before. However, Giants manager Bruce Bochy would prefer to avoid shuffling his top relievers again.
It involves a considerable adjustment for the reliever who's demoted from the closer's role, not to mention disheartening for the rest of the team -- because it probably means the ballclub has experienced some galling defeats, such as Saturday's 7-6, 10-inning loss to the San Diego Padres.
Casilla (1-3) blew his fifth save in 26 opportunities by allowing a pair of 10th-inning runs, retiring none of the three batters he faced and balking home San Diego's winning run. Contrast that with Romo's performance in a perfect ninth inning, when he preserved a 5-5 tie while striking out two batters. The right-hander has a 1.35 ERA in eight appearances during his injury-interrupted season.
Having replaced a struggling Casilla in the closer's role with Romo in 2012, then restoring the closer's responsibilities to Casilla in 2014, Bochy has proven he won't hesitate to make a switch. He'd simply rather not be placed in a position to do so.
"I don't want to get in that position where we're flip-flopping them," Bochy said. "Obviously, at times, if you have to tweak it, you do."

Until Saturday, Casilla had converted 14 of 15 save chances.
"It's been awhile since he's had a hiccup," Bochy said. "He's had a lot of rest -- maybe too much, [to] where he wasn't sharp."
That may have been the case against the Padres, who have beaten the Giants twice in a row after losing all nine of their encounters entering this series. Alex Dickerson led off San Diego's 10th by singling on a 2-0 pitch -- a tell-tale sign that Casilla wasn't sharp.
"You get behind that first batter, that's always tough," said Giants catcher Buster Posey, who also pointed out the pitch that Derek Norris hit for a subsequent single was "a little bit on the plate."
Speaking through interpreter Erwin Higueros, Casilla indicated the All-Star break interrupted his daily routine. That, in turn, would dull his effectiveness.
Said Casilla, "All the games are important to me. Losing a game, it doesn't matter how. It's always frustrating. What was more frustrating, especially for today, was that I felt really good."