Lester, who last August was diagnosed with anaplastic large cell lymphoma (a cancer that affects the lymphatic system), received an extremely positive report from his physicians.
"I just had my three-month checkup and everything came out well ... everything was normal," Lester said after blanking Buffalo on three hits during a five-inning rehab stint at soggy McCoy Stadium. "I just go three months at a time. As far as I know, the first year [checkups are] every three months. Then, once the first year is up, we'll talk about it then. I don't know what the progression is. I just know in five years, they consider you cured."
If Friday's performance against Buffalo was any indication, Lester might be able to provide a "cure" for Boston's back-end-of-the rotation problems.
Lester threw 56 of 84 pitches for strikes, topped out at 96 on the stadium radar gun and hit 94 mph once in his fifth and last inning. Altogether, he allowed three singles (including an infield hit), struck out six and didn't issue a walk. And he only allowed two Bisons to advance as far as second base.
The first was in the second inning, when Hector Luna singled with two outs, stole second and was stranded when Mike Rose struck out.
"I got a little tired at the end," Lester said, after noting he'll make another rehab start for Pawtucket on Wednesday at McCoy Stadium against Indianapolis. "But all in all, I felt strong. Obviously, in the first inning, I had some emotions and a little bit more adrenaline than I'm used to, so I probably spent a little too much energy.
"But that being said, I was happy with how I carried my delivery throughout the game."
Lester's first-inning "adrenaline" manifested itself in three quick outs, as he retired Franklin Gutierrez and Luis Rivas on grounders to short and Ben Francisco on a foul pop to first base. Moreover, the young lefty set the tone by throwing 10 of 15 pitches for strikes.
"I was really impressed with his command on both sides of the plate," manager Ron Johnson said after Pawtucket rallied for five runs in the eighth and beat the Bisons, 5-1. "You try to talk to some of the hitters on the other side, because in the Minor Leagues, you're trying to get a feel for how a guy's throwing. You can see what you see with the naked eye, but it's always neat to talk to certain guys.
"I even talked to the umpire behind the plate [Jamie Roebuck]. I asked him how his stuff looked and he said, 'Oh, man, it looks pretty good.'
"He used his offspeed stuff real well," Johnson added. "I thought he elevated the ball when he had to. I thought he pitched to the game real well. In the fifth inning, when I thought he tired a little bit, he reached back and finished up real strong."
After Gutierrez led with a single and moved up on Rivas' sacrifice bunt, Francisco hit a routine fly ball to left fielder Kerry Robinson before Lester caught Keith Ginter looking at a third strike.
Given what Lester's been through and the fact his previous three rehab starts were with Class A Greenville, Johnson still wasn't exactly stunned at Lester's performance.
"Your natural progression when you develop, and obviously a guy that's gone from Triple-A to the big leagues and had success, I kind of saw what I expected to see," Johnson said. "He commanded the zone. He threw strikes with all of his pitches. He stayed composed and pitched well enough to win.
"It wasn't surprising to me ... to look at it and say, 'Wow, that was really something.' It was probably a typical Lester performance."
Again, Lester's performance was magnified by the fact he faced more experienced hitters, especially Buffalo, which is a perennial contender for the International League playoffs.
"When you get up here, you've got a little better hitter, a little better lineup," he said. "The atmosphere is better. That helps you speed up your arm and get in the right position more often. It was nice early on to get in a little groove and take it throughout the game."
Mike Scandura is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.