"I didn't tell them what was coming this time, so I got a little more realistic look at how the stuff was," Britton said. "It's a little more competitive because they don't know what's coming, and they've got a chance to swing, even though they didn't swing a whole lot."
Britton, who is recuperating from surgery to repair a torn right Achilles tendon, is eligible to come off the 60-day disabled list May 28 but could go on a rehab assignment shortly after that.
He remains happy with how the rehab is going.
"Just kind of gets that competition going a little bit, so it was good to get that," Britton said. "Probably the best I've felt off the mound in a long time."
Darren O'Day, who is out with a right elbow injury, also threw Friday. He's not expected to need a rehab assignment, and his return is close, but not imminent, according to manager Buck Showalter.
"It was encouraging," Showalter said. "Still not quite there. Got to get the little bit still lingering in there out of there before we activate him.
"If he comes in tomorrow and doesn't feel anything, we'll move pretty quickly. Until he comes in the next day and doesn't have any residual effect, then we're not going to go there. Obviously, he's worth waiting on, and we want to get it right the first time."
Rich Dubroff is a contributor to MLB.com based in Boston.