Santiago Casilla nailed down his fourth save of the season Wednesday as the Giants stopped the A's.

Casilla has been one of the league's best relievers all season, which made it easy for Bruce Bochy to replace Sergio Romo as closer last week. Casilla hasn't allowed a run since May 16, though his peripherals suggest he's gotten a little lucky. He boasts a 1.05 ERA, 0.82 WHIP and 25/10 K/BB rate over 34 1/3 innings.

Bruce Bochy announced Sunday that Santiago Casilla will serve as the team's closer for now.

Casilla picked up his third save of the season in Sunday's victory over the Giants and had been outstanding in his setup role. Bochy also said that he preferred to use Jeremy Affeldt in his seventh-inning role where he is able to go multiple innings. Casilla should be owned and started in all mixed leagues.

Santiago Casilla tallied his second save of the season Saturday as the Giants rallied to beat the Padres.

Michael Morse hit a game-tying solo shot in the top of the ninth inning and then Brandon Belt slugged a go-ahead two-run bomb in the top of the 10th. Casilla finished off the rally by striking out two of the four batters he faced in the bottom of the 10th. He's sharing closer duties right now with Jeremy Affeldt.

Santiago Casilla will share the Giants' closer job with Jeremy Affeldt for the time being.

Sergio Romo has been demoted to a setup role. Casilla figures to see the bulk of the save chances and needs to be owned in all leagues. He boasts a 1.17 ERA with 21 strikeouts over 30 2/3 innings for the Giants this season.

Giants activated Santiago Casilla from the 15-day disabled list.

Casilla had been on the shelf since May 21 due to a strained right hamstring. He initially wasn't expected back until June 17, but with the Giants bullpen blowing leads in each of the last three games, they'll bring him back a day early. With Sergio Romo struggling, he could quickly work his way into save chances, and is worth a speculative add for mixed league owners in need of saves.

Giants manager Bruce Bochy said Friday that Santiago Casilla (hamstring) looked so good in his first minor league rehab game that they may forego his second appearance.

At this point, it looks like a near certainty that he'll rejoin the Giants bullpen before the end of the weekend. He has been sidelined since May 21 due to the strained right hamstring.

Santiago Casilla (hamstring) could be activated from the disabled list as soon as June 17.

Casilla will pitch one inning Thursday and two innings Saturday in rehab appearances with High-A San Jose before being re-evaluated to determine whether he's ready for activation. The reliever is in line to return in less than four weeks after being given a 4-6 week timetable when he strained his right hamstring on May 21.

Santiago Casilla (hamstring) will begin a rehab assignment with High-A San Jose on Wednesday or Thursday.

Casilla has recovered more quickly than expected from a Grade 2 strain of his right hamstring. He was given a 4-6 week timetable when he went down with the ailment, but it's looking like he'll wind up missing closer to three weeks.

Santiago Casilla (hamstring) could begin a rehab assignment in a few days.

Casilla threw a 30-pitch bullpen session Saturday with no issues and is nearly ready for game action. He's missed 2 1/2 weeks with a Grade 2 strain of his right hamstring and is looking like he could beat his projected 4-6 week timetable.

Giants manager Bruce Bochy said Tuesday that Santiago Casilla (hamstring) could return sooner than his projected 4-6 week timetable.

Casilla suffered a Grade 2 strain of his right hamstring less than a week ago, but he's already throwing on flat ground with no issues. Even in a best-case scenario, though, he's not going to return until well into June.

Santiago Casilla (hamstring) is expected to begin light throwing in two weeks.

He'd need another two weeks after that to get ready to rejoin the Giants' bullpen, so the reliever is looking at a late-June return. Casilla suffered a Grade 2 strain of his right hamstring during Wednesday's game.

Santiago Casilla was diagnosed Thursday afternoon with a Grade 2 strain of his right hamstring.

Casilla has already been placed on the 15-day disabled list and will likely be out for a month. The right-handed reliever suffered the strain Wednesday while sprinting down the first base line. He had a 1.37 ERA and 1.03 WHIP through 26 1/3 innings this season.

Giants placed RHP Santiago Casilla on the 15-day disabled list with a strained right hamstring.

Casilla suffered the injury Wednesday while unnecessarily busting it down the first base line on a grounder. It looked like a serve strain. He could be out a while.

Santiago Casilla will have an MRI on his right hamstring on Thursday.

Casilla injured the hamstring running out a ground ball in the ninth inning, and the injury was severe enough that the reliever couldn't put any pressure on the leg while being helped off the field. The Giants will await the results of the MRI, but manager Bruce Bochy suggested a trip to the disabled list is the likely scenario.

Santiago Casilla left Wednesday's game against the Rockies with an apparent right leg injury.

Casilla needed four pitches to get through the eighth inning, so he was allowed to bat for himself in the top half of the ninth with a four run lead. That decision backfired as Casilla collapsed in pain upon stepping on first base while running out a ground ball. The speculation is that he sustained a leg injury of some sort -- and a potentially serious one at that -- but the Giants should shed some more light on the situation shortly.

Santiago Casilla pitched a perfect ninth inning to earn the save against the Braves on Sunday.

Casilla got the opportunity to close the game with Sergio Romo having pitched in two straight days, and set the Braves down in order to earn his first save of the year. Casilla has a 1.02 ERA and 1.02 WHIP through 17 2/3 innings as the Giants' setup man this season.

Santiago Casilla is on his way to Giants camp.

Casilla was delayed for about a week due to a problem with his work visa. The 33-year-old Dominican right-hander won't need much time to get properly tuned for the start of the 2014 regular season. He posted a stellar 2.16 ERA in 57 appearances last year.

Santiago Casilla has yet to report to Giants camp due to visa issues.

Jose De Paula is also dealing with visa issues. Assuming it doesn't drag on too long, Casilla shouldn't have a problem being ready in time for the season.

Santiago Casilla worked a scoreless ninth for the save as the Giants edged the Rockies 4-3 on Wednesday.

Sergio Romo was unavailable after working three straight days, giving Casilla the chance to pick up his second save of the season. Casilla has had some injury issues this year and his 31/20 K/BB ratio in 42 1/3 innings isn't very impressive, but he has six wins and a 1.91 ERA out of the pen for the Giants.

Giants activated Santiago Casilla from the 15-day disabled list.

Casilla has been sidelined since May 20 after having a cyst removed from his knee. He owns a 1.89 ERA in 19 innings this year, and he'll likely return to the setup role.