The emergence of Jon Lester as an elite starter has caught nearly everyone off guard. Few expected that the 24-year-old, less than two years removed from chemotherapy, could possibly look so strong despite a workload that has shattered all previous career highs.

Yet the Red Sox are not entirely surprised at the development. And for that, the team can thank Indians minor-league coach Scott Radinsky.

Last offseason, Sox pitching coach John Farrell—the former head of player development with the Indians—reached out to Radinsky, the pitching coach for the Triple-A Buffalo Bisons.

Radinsky’s big-league career, which ran from 1990-2001, was interrupted for a year by a diagnosis with Hodgkin’s Disease. As such, he could offer insight into what sort of physical expectations for Lester were reasonable.

“Radinsky was the one guy (who could offer personal insight). He was very valuable,” said Farrell. “Not that every person or experience is going to be the same, but he gave us some personal insight into how he felt physically one year removed. He said that when (Lester) came back in spring training (this year), you’d see a completely different guy.”

Radinsky’s own experience suggested as much. He was a dominant left-handed reliever when he broke into the majors with the White Sox, going 22-15 with a 3.33 ERA in his first three seasons.

Just before the start of the 1994 season and days before his 26^th birthday, however, Radinsky was diagnosed with cancer. He lost that campaign while undergoing treatment, and then struggled (5.45 ERA) in his first season back in 1995.

But he had grown stronger over the course of that comeback season. Roughly eight months after his treatments had concluded, he started feeling his strength return.

He had a 2.63 ERA over the final two months of 1995. That offseason, he was able to work out at full strength. The following season, Radinsky’s career resumed its pre-cancer trajectory.

From 1996-98, he produced a 2.65 ERA while averaging 65 appearances a year. Based on that experience, Radinsky told Farrell that it was fair to assume that Lester might be ready to regain his elite prospect status around this year.

“We were about the same age when it went down…(Lester) is right on track. He’s the same way I was,” said Radinsky, who is with the Indians’ major-league club for the rest of this year. “It doesn’t surprise me that he’s rebounded to what he is. I think it’s expected. You give yourself enough time and you’ll be back to normal.”

Radinsky (who spends his offseasons fronting the punk band Pulley) made a point of striving not merely to return to the status that he had enjoyed prior to his diagnosis, but to advance his career to new levels. In Lester—who is physically robust following a vigorous offseason—he sees a similar development.

“You just push yourself to be better than you were before,” said Radinsky. “There are benefits to hard work. It does pay off. I found that out first-hand, as he is doing as well. Once you start pushing yourself, you can get back to that elite level you want to be at.”

Entering this year, some talent evaluators from other teams wondered whether Lester would ever move beyond his inconsistencies and command struggles of 2006 and 2007. Questions loomed about whether the southpaw could reclaim the status he had achieved as one of the top pitching prospects in baseball in 2005.

Radinsky did not have such doubts. If Lester was on track to become one of the better pitchers in the game prior to his diagnosis, then the physical reality was that he should still be able to do so.

“This was just a little derailment,” said Radinsky. “He’s only 24. He’s supposed to get better. He’s getting better naturally. He’ll catch back up, get back in the shape he’s supposed to be in, perform that way and then some.”

That perspective was a powerful one for Farrell. The Sox pitching coach had seen Lester first-hand in 2005, when the 21-year-old featured a mid-90s fastball and nasty off-speed offerings in the Portland Sea Dogs rotation.

If the Sox could reasonably expect him to return to that form, Farrell expected that Lester could emerge as a front-of-the-rotation starter in the majors. That view helped the club to assign a value to Lester, both as the Sox contemplated the possibility of an offseason trade for Johan Santana and then as the team projected the shape of its 2008 rotation.

“(The conversation with Radinsky) affected what we might expect, on what we might project to get out of (Lester) starting this year,” said Farrell. “It was a valuable piece of information when it came time to determine what we had going into next year and how do we project the whole starting rotation of the pitching staff with him in it. We had more knowledge, more experience of what we viewed his potential to rise to.”

Still, even in their most optimistic forecasts, the Sox did not anticipate Lester’s revelatory 2008 campaign. Lester has pushed himself into the top 10 in the American League in wins (15), ERA (3.26) and innings (204.1). He has emerged as one of the top starters in baseball, a rotation anchor who has been the most valuable pitcher on the club.  

“We didn’t know he’d grow to this point with the consistency of the performance,” admitted Farrell. “(But) his performance is matching the things you can visibly see: the physical strength increase he’s made, the weight gains that he’s made.

“All those things line up and add up to the velocity he’s now throwing at. He’s done a great job of maintaining that, adding a two-seamer, which has been a huge thing for him. All those things combined have really given us one hell of a starter.”

Alex Speier is a Senior Writer for WEEI.com. He can be reached at aspeier@weei.com.