VIERA, Fla. -- After battling dehydration last week, no chances were taken with ace pitcher John Patterson on Wednesday.

"I had a trainer sit next to me all day today, handing me one cup of water after another," the righty said.

The trainers had nothing to worry about, as Patterson dazzled in his final start before Opening Day. He was slated to throw 90 pitches, and made them last for almost seven innings. Among those pitches was a mix of everything in Patterson's repertoire.

"All my pitches were working pretty well today," he said. "The cutter was good, the changeup was really good, and the curveball had a good snap on it."

Manager Manny Acta said he was impressed by the outing, but cautioned not to read too much into the numbers, because it was against Baltimore's split squad.

Patterson will become the anchor of a rotation that also includes, in order, Shawn Hill, Matt Chico, Jason Bergmann and Jerome Williams. It's a young staff, but catcher Brian Schneider has been impressed so far.

"It's not that they're cocky, but they have a lot of swagger," he said. "They know they're up here and they belong, and, hopefully, that carries over to every start."

Acta said that during the season he'd like all the starters to throw about 100 pitches per outing, and will never throw them for more than 115 or 120. He added that youth won't play into his decisions, because he wants to see if the players can succeed in the big leagues. Chico is the youngest, having no Major League experience.

"We're going to approach him just like any other pitcher," Acta said. "We're not going to baby him, because we want to see if he can handle this."

Colome added: The Nationals selected the contract of right-handed pitcher Jesus Colome from the Triple-A affiliate in Columbus. The announcement clears the way for the team to carry 12 pitchers on its roster.

The final 25-man roster will be announced after Saturday's exhibition game against the Orioles, and, assuming no trades or injuries, will include Colome, not fellow reliever Saul Rivera or infielder Kory Casto.

Acta said that in a tight pitching market, it's important to retain good arms when they are found, a category that Colome fits in.

"He's pitching better than we've ever seen him before," Acta said. "It seems like he's pitching now more than throwing, and he's showing that arm strength that's there."

Catching situation: After a strong camp, Rule 5 Draft pickup Jesus Flores has left no doubt that he'll be on the Opening Day roster.

He's currently the No. 2 catcher behind Brian Schneider, who will catch between 140 and 150 games this season. That doesn't leave a lot of time for Flores.

"I'll just keep working hard and waiting for the opportunity to show them I can play," he said. "So far, it is going really well. I'm trying to learn everything they teach me."

He said that Schneider has helped him out by providing some tips on what to expect from the different pitchers on the staff. He's also helped his own cause by batting well, including several big hits against Major League pitching.

With Flores in place as the backup catcher, Robert Fick is freed up to be a utility player, used wherever the coaching staff decides he is needed on a daily basis. Acta said it was tough for Fick to adjust to that position.

"At the beginning of Spring Training, I heard him say he wanted to be the everyday this or the everyday that," Acta said. "He has finally come to terms and accepted his role, which is the biggest thing, and he takes pride in that."

Wagner's work ethic: For the first time, reliever Ryan Wagner entered Spring Training with the knowledge that he would end it on a Major League roster. That doesn't mean he's changing his grueling workout schedule, though.

"I'm still going to show up at 7 every morning and try to be one of the first guys here," he said. "I'll work just as hard as if I was the low man on the totem pole."

Towards the end of 2006, Wagner began to work on his mechanics with pitching coach Randy St. Claire. He returned to the sidearm motion that had worked in the early part of his career, and feels that he is ready to throw consistently through an entire season.

"There are a few adjustments here and there, but I feel that I'm right where I need to be," Wagner said. "Now it's just going after hitters and their weaknesses."

Nook Logan update: Acta joked that he would like Spring Training extended for another week "just to make sure Logan is fine." It looks like he may not need that extra time, though.

The center fielder continues to recover from a groin injury he suffered against the Cardinals. He completed a full slate of running exercises on Wednesday, and Acta remained hopeful that he would play in one of the team's exhibition games this weekend.

He is unlikely to play in Thursday's game, but could start as soon as Friday. If he is unable to play on Friday or Saturday, Acta may send him back to Florida for a Sunday Minor League game, because he wants Logan to get game experience before rejoining the team.

Transactions: Four players were played on the 15-day disabled list: first baseman Nick Johnson, outfielder Alex Escobar and pitchers Luis Ayala and Mike O'Connor.

The team also announced which additional players will make the trip to Columbus and Norfolk for exhibition games this Thursday and Friday. Because the games take place so close to the beginning of the season, Acta will bring extra players along to ensure the starters get adequate rest.

Traveling with the team will be Roger Bernardina, Abraham Nunez, Chris Booker, Mike Bacsik, Larry Broadway, Tony Blanco, Brandon Harper and D'Angelo Jimenez.

Up next: The Nationals leave Florida and will face the Baltimore Orioles in a pair of exhibition games. On Thursday, the teams will play in Columbus, Ohio, at 4:05 p.m. ET, and on Friday, they will play in Norfolk, Va. at 2:05. Hill will pitch on Thursday, and Chico pitches on Friday. Orioles pitchers are to be determined.