Athletics rotation is hurting as Blackburn goes on injured list

The Athletics placed starting pitcher Paul Blackburn on the injured list Monday as their previously durable five-man rotation was down to two healthy pitchers.

Blackburn, the A’s most consistent starter with a 3-2 record and 4.14 earned run average, went to the 10-day I.L. retroactive to May 11 with a stress reaction of the fifth metatarsal on his right (or push-off) foot. The move comes in the wake of manager Mark Kotsay saying Sunday night left-handed starter Alex Wood has been dealing with a shoulder issue that could need additional rest.

“Alex has been grinding,” Kotsay said told reporters Sunday. “He hasn’t felt great. He’s been able to make every start. But you saw a little drop in velo and his slider wasn’t as sharp. He gave us everything he had for two innings.”

Wood lasted two innings against Seattle, giving up five runs (one was earned) before being pulled after 60 pitches. The Athletics’ Opening Day starter is 1-3 with a 5.26 earned run average in nine starts.

Easton Lucas, optioned to Las Vegas two days ago, was recalled from Las Vegas.

With starter Joe Boyle (lower back) already on the I.L., the lone two healthy starters that began in the season in the rotation are Ross Stripling, scheduled to start Monday night in Houston, and J.P. Sears, who will pitch Tuesday. The A’s had stayed on rotation with those five players until a May 7 doubleheader against the Texas Rangers.

The only other starters the A’s have used this season were Osvaldo Bido, called up as the 27th roster spot for the Texas doubleader, and Joey Estes, the winning pitcher Saturday giving up one earned run in five innings against Seattle.