FORT MYERS, Fla. -- If the Red Sox were at all wary of handing Jon Lester a five-year contract extension, Lester on Saturday made certain to ease those qualms. On a quiet back field at the team's Minor League complex, one day before a Sunday announcement that will presumably make his extension official, Lester provided what could be a glimpse into the next five years.

Despite using the outing to experiment with his changeup and curveball, Lester still managed to strike out eight Minor Leaguers over his four innings, giving every indication that he's already in midseason form.

"I wanted to do well, to go down there and be competitive, and have a good tempo and a good intensity with it," Lester said. "Because if you don't, you get nothing out of it."

Lester got something out of it.

Along with a rather clean stat line -- especially at this time of year -- Lester managed to gain a better feel for his curveball and a bit more confidence in his changeup. He struck out one Minor Leaguer, Carlos Maldonado, on a changeup, his 62nd and final pitch of the day. Lester allowed only three singles and a walk, despite what he called an inconsistent curve.

"At times, I felt pretty good with it," Lester said. "At other times, it felt terrible."

"It's not as sharp and as powerful as he's shown, even earlier in camp here," pitching coach John Farrell said of the curveball. "Nothing of great concern, by any means. It's a matter of repetition and consistency here with him."

Next up for Lester is a Thursday night start against the Reds in Sarasota, Fla., though he won't be able to escape attention in the ensuing four days. The Red Sox have said that they will make an announcement regarding Lester at some point on Sunday morning, presumably to reveal the five-year, $30 million contract extension that Yahoo Sports reported earlier this week.

The deal includes a $14 million option for 2014 and was reportedly contingent on a physical, which may explain why Lester was in Fort Myers on Saturday to begin with.

Originally scheduled to start the team's Grapefruit League game in Fort Lauderdale, Fla., more than a two-hour bus ride to the east, Lester instead stayed back to pitch in Saturday's Minor League game. Farrell dismissed the change as a chance to control Lester's pitch count -- he kept pitching in one inning even after recording three quick outs -- and to give others an opportunity in the Grapefruit League game. But in addition to those bonuses, the switch also likely gave the Sox a chance to administer the physical.

What it didn't do was give Lester a chance to impress manager Terry Francona, who traveled with the rest of the team to Fort Lauderdale. But this spring -- unlike the last one -- Francona doesn't need to be impressed.

"This year, I think, is a lot nicer, because I know my role, I know what I'm doing and now I have to just prepare for the season," Lester said. "I know that if I go out there and I don't pitch very well, I'm still going to be on the team. So I think it's a lot nicer to come in and know where I'm at, and just be comfortable enough to just go out and pitch"

Had Lester spoken before his scheduled four innings in a Minor League game on Saturday, his words may have sounded like a disclaimer.

"You don't have to go out every outing and throw nasty pitches," Lester said. "If I walk guys, it's no big deal. It's Spring Training. We'll work on things. We're pitching away from my strengths."

Yet of his 62 pitches, 39 were strikes. Lester retired 12 of the 15 batters he faced, and would have fared even better if not for the inning that was artificially extended. Boasting what Farrell called "surprising" velocity at this point in spring, Lester threw first-pitch strikes to the first five batters he faced, and to nine Minor Leaguers in all.

"Everything felt good," Lester said. "I think we're going in the right direction. We're definitely not going backwards, which is always a good thing."