He’s on a roll like none other during his career. Even when Rick Porcello went 5-0 in July three years ago, it was nothing like this. Then again, not many pitchers throw consecutive complete-game shutouts, and fewer still accomplish it when one of the gems doesn’t include a walk or a strikeout. But that’s the kind of game Porcello pitched at Comerica Park on Tuesday night in a rapid, 3-0 victory over the A’s. He didn’t strike out anyone. He didn’t walk anyone. He allowed four hits, one more than he gave up to Rangers last week. But his streak of 251⁄3 scoreless innings dates earlier than the Rangers game. It also includes the six scoreless innings he threw on the road against the Indians on June 20 and 11⁄3 innings of the way he finished against the Twins on June 13. No wonder there’s a ton of All-Star talk about him now. Porcello’s earned such talk. And because he’s pitched well most of the season, it’s also no wonder he is tied for the American League lead in victories with an 11-4 record. Granted, he would have liked to have had at least one strikeout against Oakland — so that it couldn’t be said that he is the fourth Detroit pitcher, and the first since Dizzy Trout in 1944, to throw a complete-game shutout without a walk or a strikeout. But keep this in mind, as Porcello himself does: To pitch this effectively is difficult. In his two worst games this season, Porcello allowed 12 earned runs on 22 hits in 112⁄3 innings. So, to allow only seven hits in back-to-back shutouts is a feat to be savored. “I gave up so many hits early my first five years, I finally figured out where not to throw the ball,” Porcello said. “I would have liked to have had a strikeout, but I’ll take a game like this over anything.”