When Flaherty was in the minors, Casilla and Yamaico Navarro split time at second. Navarro's stay was short-lived. He was optioned back to Norfolk after three starts and was designated for assignment Tuesday.

Casilla's playing time has been sporadic. Showalter said he likes having Casilla's speed — he's been successful on 26 of his 28 stolen-base attempts over the past two seasons — as a late-inning weapon off the bench. While he has fine defensive range, Casilla has never been able to hold on to a starting job in his career. The club invested $1.9 million in Casilla this offseason — he has a $1.7 million deal this year and a $3 million 2014 option with a $200,000 buyout — but he is hitting just .211 in 71 at-bats.

"The most important part of the position is turning the double play, and [Flaherty and Casilla] have done a good job of that," Orioles executive vice president Dan Duquette said.

Looking forward

Asked if the club would be interested in upgrading the second base position by trade, Duquette has said he's happy with the existing options. Plus, the pool of pending free-agent second basemen who could be available on the trade market isn't a deep one. Besides the Philadelphia Phillies' Chase Utley, who has also dealt with a number of injury issues, the best options that could be available are light-hitting Los Angeles Dodgers infielders Skip Schumaker and Nick Punto.

The Orioles' future at the position greatly depends on the development of 21-year-old Jonathan Schoop, the organization's top position-player prospect. The Orioles see promise in Schoop, who played well in the Arizona Fall League and for the Netherlands in the World Baseball Classic. But Schoop is on the disabled list with a stress fracture in his lower back. He could still be an option at some point this season, but probably not until August at the earliest.

"He's young," Duquette said. "He needs a little more seasoning. No question about that. He's a real capable kid. He's highly regarded. He's got some serious power. He can play second base. He has good hands and a good arm."

While Schoop, who came up as a shortstop, has played second base for most of the past two seasons, he could end up at third if his power projects there, especially if the Orioles eventually transition Manny Machado to shortstop.

As for Roberts, he hopes to dictate how the the position shakes out for the rest of this season. He realizes these might be his final months in an Orioles uniform, and if that's the case, he wants to make the best of it.

"I was fortunate enough to be here my whole career," Roberts said. "And the Angelos family and the Orioles put a lot of trust in me to play, and I haven't been able to do that as much as I'd like, so I feel like this is kind of a last breath of fresh air for me now.

"Our organization's in a really good place and for me to be able to hopefully come back and contribute for the last half of the season and contribute to something special, no matter what happens next year, wherever I am or am not, that would be something that would be pretty special for me."