Jon Lester ladled out a healthy dose of diplomacy last night when a reporter asked the big lefty if both he and the Red Sox were ready to go on one of those sizzling summertime rolls that just a few years ago was a staple of the Boston baseball experience. Like a contestant on a game show, Lester chose to answer the second part of the question first: “I think the team’s been doing pretty good,” he said. “I think I’ve thrown the ball better at times, better than what my line scores have shown, and there’s been some bad ones mixed in.” And so on. He had just pitched seven strong innings and taken a no-decision in the Red Sox’ 2-1 victory against the San Diego Padres, which ended when Johnny Gomes rocketed a Luke Gregerson pitch into the Monster seats for a pinch-hit, walkoff homer in the ninth. The blast reduced Lester to the postgame undercard, which would explain why he chose to talk about what the team is capable of doing. Here’s the problem: It wouldn’t do a lick of harm if the guy mixed in a little Clemens-Pedro-Schilling brashness now and then. So a little later on, after Lester had done the media meet-and-greet, I asked him: How about Lester going on a roll? How about he roars through July and right into August, blowing away opposing hitters and being the ace that he’s supposed to be? If you’re a Red Sox fan, here’s the good news: Lester absolutely, positively believes that can happen. Heck, not only did he agree that he could go on a roll, he went so far as to brush aside the notion that he could win, say, seven in a row.