Red Sox activate LHP Rich Hill

CHICAGO -- The Boston Red Sox activated left-handed reliever Rich Hill from the 15-day disabled list and optioned fellow lefty reliever Justin Thomas to Triple-A Pawtucket on Friday.

Hill, who underwent Tommy John surgery in June 2011 and was expected to be back in the majors by May, returned to the Red Sox bullpen slightly ahead of schedule. In three levels in the minors this season, Hill had 18 strikeouts, two walks and a 2.00 ERA in nine innings.

"All the work that we did this offseason, everything from the lifts and the workouts in the gym to the shoulder program, everything's really starting to pay off," Hill said. "As far as the rehab part, all the work that I put in, now that it's over with, it's finally go time."

Once a starter with the Chicago Cubs and Baltimore Orioles, Hill has reinvented himself as a side-arming lefty specialist since joining the Red Sox in 2010. Hill said the ball was coming out of his hand with more life, adding that he believes he's even added a couple miles per hour to his fastball. Hill credited his quick recovery and improved fastball to the strengthening program put together for him by Red Sox rehab coordinator Mike Reinhold and his physical therapist John Pallof.

When asked what type of role Hill would fill, manager Bobby Valentine was quick to respond.

"Left-handed reliever," Valentine said with a smile, before going into slightly more detail. "Not too early and not too long."

Valentine wasn't sure if he'd use Hill only against lefties, but pointed out that he had done well when facing right-handed batters during his nine innings rehabbing in the minors. As far as Hill was concerned, he was just happy to be back and help a bullpen that has a league-worst 6.79 ERA in any way that he can.

"I know I can get both righties and lefties out, but (I'll do) whatever the need is here for this team to win," Hill said. "Everybody has to donate and give their role, kind of step aside from themselves. If I think, 'I'm not a lefty-specialist,' your role is to help the team win, that's the bottom line."

Thomas had struggled out of the bullpen this season, an area the Red Sox have been looking to shore up just 18 games into the season. In 4 2/3 innings of work, Thomas has a 7.71 ERA and has allowed 10 hits and two walks.

Valentine also provided updates on several other injured Red Sox.

Left-handed pitcher Andrew Miller is recovering from a hamstring injury.

"(GM) Ben (Cherington) talked to him when Rich came up," Valentine said. "(Miller) feels he's close, we feel he's close, just a little more consistency. But he's throwing well."

Miller has struck out 12 but also has walked 10 in 6 1/3 innings while rehabbing with Pawtucket. He's allowed four runs during that time, all of which came in one bad outing. When Valentine talks about consistency, he's clearly looking for Miller's walk total to come down, something he's struggled with (5.4 career BB/9) when facing major league hitting.

Outfielder Cody Ross -- who left Wednesday's game in Minnesota after twisting his right knee and was held out of Thursday's opener with the White Sox -- was back in the lineup on Friday night, hitting sixth. Valentine said Ross was fine and had a "bounce in his step." Ross leads the Red Sox with five home runs. He's another weapon to add back to the Red Sox's potent offense, which has averaged more than eight runs over the past five games.

Center fielder Jacoby Ellsbury is dealing with a partially dislocated/subluxed shoulder.

"Every day he's moving along in the range of motion and the strength," Valentine said. "He was carrying a banana the other day."

With the Red Sox offense clicking and his team on a four-game winning streak, Valentine was able to joke about his star center fielder. Despite wielding potassium-rich fruits, Ellsbury isn't quite ready to swing a bat.

Sahadev Sharma is a special contributor to ESPNBoston.com.