FORT LAUDERDALE, Fla. -- The Orioles made one roster decision and previewed another Thursday, when they endorsed Kevin Millar as cleanup hitter and said that an announcement on the Opening Day starter could come on Friday. Baltimore manager Dave Trembley made both statements in the hours before his team's game in Port St. Lucie.

Baltimore's former cleanup hitter and staff ace -- Miguel Tejada and Erik Bedard, respectively -- were shipped out in a pair of offseason trades. Trembley has consistently said that any of his starting pitchers could conceivably pitch on Opening Day, and he's steadfastly maintained an interest in seeing Millar as the hub of his lineup.

"If I was going to write the lineup tomorrow, Millar would be the cleanup hitter," he said Thursday. "To start the season -- that doesn't mean he'll stay there. ... I think he sees a lot of pitches. I think he always comes up with one very good at-bat per game. Millar has a knack for doing that. He usually is a very good two-strike hitter and a good two-out RBI guy."

The top of the lineup -- Brian Roberts, Melvin Mora and Nick Markakis -- is fairly well established. Both Roberts and Mora are two-time All-Stars, and Markakis is the team's best young position player. The fourth slot is important to the Orioles because they had a middling power output last season and didn't add much offense over the winter.

Millar batted fourth in 36 games last year, notching a .260 batting average, a .366 on-base percentage and a .435 slugging mark. He batted fifth more often, but not quite as successfully.

Trembley said he'll likely hit veterans Aubrey Huff fifth and Luke Scott sixth, allowing the Orioles to split up their left-handed hitters and their right-handed hitters.

Millar said he felt comfortable batting fourth and that he liked the idea of batting behind Markakis and in front of Huff. Both Millar and Trembley singled out catcher Ramon Hernandez as a key offensive player for next season. Trembley will likely bat Adam Jones low against right-handers and higher against southpaws, but Millar will be a constant presence.

"Am I going to hit 40 home runs? No, but I'll give you a tough at-bat," Millar said. "And I think that's how we need to battle as a group. If you look around this locker room, we don't have a 40-home run guy. But we'll give you good at-bats."

Trembley didn't drop any more hints as to his Opening Day starter, but said he would name one after Steve Trachsel and Jeremy Guthrie pitch through their respective duties on Friday. Guthrie is scheduled to pitch and Trachsel is scheduled to work in an intrasquad game, and Trembley said he'll wrap that race up in the aftermath.

Both Guthrie and Trachsel are expected to be candidates, as is southpaw starter Adam Loewen.

"After Guthrie and Trachsel pitch [Friday]," said Trembley, "we'll be ready to name our Opening Day starter."