Way back in 2010, the scouting department of the Cleveland Indians envisioned Drew Pomeranz pitching in big games. The Indians drafted the big lefty out of Ole Miss with the fifth overall pick and signed him for $2.6 million. He was the second pitcher taken – behind Jameson Taillon – and went ahead of Matt Harvey and Chris Sale. Though he no longer pitches for Cleveland – that was four teams ago – Pomeranz’s big game is here. He takes the ball for Boston today at Houston’s Minute Maid Park with his team down 1-0 in the best-of-5 American League Division Series. Pomeranz (17-6, 3.32 ERA) got the win against the Astros last week in the victory that secured the AL East title. That was a big game, too. But this is certainly bigger. It’ll be Pomeranz’s first postseason start. And he’s facing an Astros team that raked Red Sox pitching – including Sale — for 12 hits and eight runs in Thursday’s opener. And he’ll be opposed by Dallas Keuchel, the 2015 Cy Young Award winner who is 14-5, 2.90 ERA. Pomeranz may be able to draw on his success from last week, when he checked the Astros on three hits and a lone run in six-plus innings. “Kind of goes both ways,” Pomeranz told masslive.com. “They got to see me; I got to see them.” And that was at Fenway Park, with the backing of Red Sox Nation. Today will be different. And so much bigger. … It’ll be interesting to see if former Mississippi State standout Mitch Moreland, a lefty hitter, is in the Boston lineup against left-hander Keuchel. The Red Sox might want Moreland at first base for his defense.