Five months ago, the Red Sox signed Dustin Pedroia to an eight-year contract extension that preempted the second baseman’s potential free agency after next season and may have guaranteed he will finish his career with the team. Now, it may be Jon Lester’s turn to follow suit. General manager Ben Cherington reiterated yesterday that the Sox expect to broach the subject of a contract extension for Lester, although it likely won’t happen until late in the offseason or during spring training. The lefty, who turns 30 in January, is coming off a postseason for the ages, having gone 4-1 with a 1.56 ERA in five starts. “He’s a key guy,” Cherington said during the Sox’ uneventful second day of the winter meetings. “He’s been a horse for us for a long time and didn’t show any signs of slowing down this October. Obviously, he’s a guy we would like to keep. I think there will certainly be a willingness to have a conversation, so we’ll see where it goes. But we haven’t done that yet.” There isn’t any rush. Lester isn’t eligible for free agency until after next season, and with a strong year, he could be in line for a five- or six-year contract worth about $20 million per season. Philadelphia Phillies lefty Cole Hamels, one month younger than Lester and with similar career achievements, signed a six-year, $144 million extension in 2012. If Pedroia entered the market, he likely would’ve gotten a deal even more lucrative than the eight-year, $110 million extension. But like Lester, he was drafted and developed by the Red Sox, and he prioritized staying with the only organization he ever has known. In time, the Sox will find out if Lester feels the same.