SAN FRANCISCO -- Brian Wilson is making slow progress in his comeback from elbow inflammation and Giants manager Bruce Bochy is unsure whether the All-Star closer will be ready to come off the disabled list next week when he's eligible.

Wilson played catch for 6-7 minutes Thursday before San Francisco's game against Houston. He did not report any setbacks, according to Bochy, and the team will wait a day to see what the next step is for Wilson.

"We'll see how he feels tomorrow," Bochy said. "It's part of the rehab that he'll (go) through. Tomorrow we'll evaluate him and see what the next move is."

Wilson has 35 saves this season but hasn't pitched since Aug. 15 when he allowed three runs in two-thirds of an inning and took the defeat in a 6-4 loss to the Atlanta Braves.

The Giants hope the right-hander can come off the DL next Wednesday, but Bochy hesitated when asked if he thought that would happen.

"I wouldn't rule it out, but it's going to be tough for him to be ready to go when his time is up," Bochy said. "We'll see where he's at tomorrow and then make a call."

Wilson, last season's major league saves leader with 48, is one of four San Francisco pitchers currently on the DL.

The Giants, who began the night two games behind first-place Arizona in the NL West, claimed Padres closer Heath Bell off waivers earlier this week. Bell may never pitch for San Francisco, however.

San Diego has 48 hours from the time Bell was claimed to decide whether to work out a trade for the three-time All-Star or pull him back off waivers.

Right-hander Santiago Casilla pitched the ninth inning for San Francisco in Wednesday's 2-1 win over San Diego for his first save of the season and may continue in the closer's role until Wilson returns.

"I was impressed with what he did," Bochy said. "That was encouraging to see."

San Francisco's pitching staff also has been beset by injuries to Barry Zito, Jonathan Sanchez and Sergio Romo.

Zito (mid-foot sprain) and Romo (elbow inflammation) are both scheduled to begin throwing off the mound Friday, while Sanchez (sprained ankle) has yet to resume throwing.

Additionally, Bochy hinted that outfielder Nate Schierholtz could be headed to the disabled list to make room for center fielder Andres Torres when Torres comes off the disabled list this weekend.

There was some encouraging news for the defending World Series champs, though.

Giants catcher Eli Whiteside was activated from the disabled list and was in the starting lineup against Houston. Whiteside had been on the seven-day disabled list after hitting his head while attempting to steal second base against Atlanta on Aug. 17.

To make room on the 25-man roster, backup catcher Hector Sanchez was optioned to Class-A San Jose.