ST. PETERSBURG -- To make room on the active roster for Saturday starter Clay Buchholz, the Red Sox optioned infielder Mauro Gomez to Triple-A Pawtucket.

Gomez started Friday night at first base for the injured Adrian Gonzalez and went 0-for-4 with two strikeouts and a double-play groundout. With Gonzalez still sitting and Gomez gone, Red Sox manager Bobby Valentine opted to start Brent Lillibridge at first base Saturday night against the Rays, his fourth start with Boston and his first in the infield.

Valentine said he feels comfortable with Lillibridge at first base against Rays left-hander David Price, but the skipper could start David Ortiz there in Sunday's series finale against Tampa Bay right-hander James Shields. The manager hadn't approached Ortiz with that idea but said he'll play there if he wants to. Valentine also mentioned Nick Punto and Jarrod Saltalamacchia as possibilities at first base in Gonzalez's absence.

Gomez, 27, had been recalled for his second stint with the Red Sox on July 3. He has played in eight games with Boston this season, batting .308 with three doubles, three RBIs, two runs and a walk. He was named the starting designated hitter for the 2012 International League All-Star team and entered Saturday batting .311 for the Pawtucket Red Sox.

Adrian out of Red Sox's lineup with back spasms

ST. PETERSBURG -- Adrian Gonzalez was out of Boston's starting lineup for the second straight game Saturday and is considered "real doubtful" for Sunday's series finale due to lower back spasms.

Red Sox manager Bobby Valentine decided it was best to sit Gonzalez, who hadn't missed a game this season and has played 159 or more every year since 2006, rather than risk having to place another star player on the disabled list. The first baseman said he's never had an injury like this before, but he's "not at all" concerned about it after talking to other players who have had similar spasms.

Valentine projected Gonzalez would be back in the lineup by the beginning of next week, and Gonzalez figured it would take three days at the most.

"We're being real cautious," Valentine said. "He has a little situation in his lower back that came on quickly and hopefully will leave quickly."

Gonzalez was a late scratch from Friday's lineup. He said his back locked up on him earlier in the day when he was walking around, stopped to greet family and bent down to talk to a child. When he stood back up, he started to feel discomfort. He told Valentine he could play and tried to go through his normal pregame routine while getting treatment, but it wasn't feeling up to par.

He limited his pregame activity Saturday to just swings off a tee right before the game in case he's needed to pinch-hit. He actually made his way to the on-deck circle Friday night in the seventh inning, but when the Rays intentionally walked David Ortiz, Gonzalez jumped back in the dugout and Mauro Gomez took his turn. Gonzalez said he could have hit, but he would have been "swinging all arms."

"He's being cautious with me and so are the trainers. I felt better today," Gonzalez said. "There's still tightness there. If I need to, I can go out there. But they don't want me to push it and aggravate it."

Ciriaco opens eyes with historic three games

ST. PETERSBURG -- Mentioning Pedro Ciriaco and Ty Cobb in the same sentence might be considered baseball blasphemy to some, but Boston's fill-in second baseman earned the distinction with his play as of late.

Ciriaco went 0-for-4 in his Red Sox debut last Saturday, then recorded at least three hits in his last three games while also stealing a base in each contest. He's the first Red Sox player ever with at least three hits and a stolen base in three straight games and the first Major Leaguer to do that since Johnny Damon in 2000. And the only player to ever do that in four straight games is, yes, Ty Cobb in September 1927.

"He is hot," manager Bobby Valentine said. "That's more than hot, isn't it?"

Ciriaco has only played 35 Major League games between Pittsburgh (2010-11) and Boston, but he's hitting .418 (23-for-55) in that time, giving him the second-best average in a player's first 35 games, with a minimum of 50 at-bats. John Kroner hit .422 (43-for-102) for the Red Sox from 1935-36.

In addition to his unusual statistical accomplishments, Ciriaco has earned praise from his teammates and the respect of opposing clubs.

"He did a nice job. He's very fast. We've seen him in Spring Training before," Rays manager Joe Maddon said. "We've always kind of liked him from a distance. He's very athletic. He does know how to bunt. Right now, he's being a pain in the butt -- to their advantage and to our detriment.

"He plays with a lot of energy. He's an interesting player, no question."

Worth noting

• Carl Crawford went 0-for-4 with an RBI, a walk and a stolen base while playing nine innings in left field for Triple-A Pawtucket on Friday night. He was scheduled to play nine innings in left again Saturday night. Valentine said he heard Crawford felt good Friday and is still getting closer to returning, potentially as early as Monday.

• The Red Sox's bullpen combined for four innings Friday night and allowed only an unearned run. It was the ninth time this season Boston's relief corps has held an opponent without an earned run over at least four innings. Since April 23, the Red Sox's bullpen has pitched to a 2.10 ERA, the best mark in the Majors entering Saturday.