Estrada's next scheduled start would have been Saturday against the Phillies. The team's rotation was already in limbo, with Hiram Burgos on the disabled list with a right shoulder injury and Mike Fiers having just been sent down to Triple-A. If the Brewers do place Estrada on the DL, they could recall Fiers, who was home in Florida on Tuesday visiting his ill mother. If they decide Estrada does not need a stint on the DL, Fiers would not be eligible and the Brewers would have to summon a different arm from the Minor Leagues.
Estrada felt a "pop" in his hamstring delivering a pitch in the fifth inning of Monday's 10-2 loss to the A's, and it was all but certain a day later he would be unable to pitch on Saturday.
"I think that's what's going to happen," Estrada said about missing the start. "I can walk on it, it's fine, it's just that when I get to that one point where I have to put pressure on it and extend my leg, that's when it hurts. Obviously, I need to do that to be able to pitch.
"I don't know if this start is going to happen or not. It doesn't look very good right now. We'll see what happens. I'm not too happy right now."
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. Kevin Massoth is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.