Aurilia, 34, was the Reds' Opening Day shortstop, but he hit just .198 in his first 25 starts at the position. On May 11, he was placed on the 15-day disabled list with a strained left hamstring, opening up the door for Felipe Lopez to take over the starting duties at short.
Upon his return from the DL, Aurilia vastly improved his performance at the plate. He hit .306 with 11 home runs and 56 RBIs after his return.
But Aurilia often voiced his displeasure with his playing time when he came back from the injury. Lopez was the everyday shortstop, and Aurilia was reduced to a utility role. By the end of the season, though, he had established himself as the go-to man at second base. He made 64 starts at the position.
Ryan Freel, who made 48 starts at second base in '05, is available to take over at the position, but he will likely remain in a utility role, O'Brien said.
"Right now, his greatest asset would be in a multipurpose role," O'Brien said. "But we also know if he needs to play more regularly at second base, he's capable of doing that."
Another option is prospect William Bergolla, who spent the majority of this season at Triple-A Louisville but also saw 17 games at the big-league level.
"He's still maturing at the position," O'Brien said. "But he's got some skills."
Should the Reds be unable to work out a deal with Aurilia, O'Brien is not ruling out the possibility of signing another veteran infielder to clear up the hole at second.
The decision not to exercise Ortiz's $4.55 million option wasn't a major surprise. The right-hander battled an early groin injury and went on to post a 9-11 record and 5.36 ERA in 30 starts in '05.
Was it simply a matter of his numbers not being worthy of such a hefty salary?
"That would be a concise, accurate summary," O'Brien said.
Ortiz remains on the roster as arbitration-eligible for the time being.
"He's a controllable player on the roster," O'Brien said. "We intend to have further dialogue as we would any other arbitration-eligible player. I can't predict the outcome."
Aurilia will also remain on the roster until he officially files for free agency.
In other news, pinch-hitter Jacob Cruz has filed for free agency. He batted .236 with four home runs and 18 RBIs in 110 appearances and led the National League with a club-record 20 pinch-hits.
The Reds also hired Jim Pransky as a professional scout on Friday. Pransky had been previously serving in the same role with the Athletics.