The Astros have decided on a No. 1 starter — for the opening of spring training.

Righthander Lucas Harrell is expected to take the mound Saturday against Philadelphia in Clearwater, Fla., while righty Bud Norris will get the nod Feb. 24 when the Astros open at Osceola County Stadium against the New York Mets.

Astros manager Bo Porter said Sunday his starters likely will pitch two innings during their first spring training appearance, then increase activity as April approaches.

Between an extended seven-week stay in Kissimmee due to the World Baseball Classic and the Astros’ having at least seven pitchers competing for the final two spots in the starting rotation, as many as three starters could take the ball during one game.

“We’ll make sure that everybody gets a fair opportunity,” Porter said.