Right-hander Clay Condrey felt even better. The Phillies activated him from the 15-day disabled list, where he had been since July with a strained left oblique.
Phillies manager Charlie Manuel said Happ, who has not pitched since Sept. 2 because of a strained intercostal muscle, could start Friday against the Braves at Turner Field. Eyre, who has not pitched since Sept. 7 because of a bone chip in his left elbow, felt encouraged after playing catch before their series opener against the Nationals.
Happ threw a 55-pitch bullpen session Monday. He will throw a shorter bullpen Wednesday.
"The way it felt [Monday] is definitely a positive," Happ said. "I felt good. Fifty-five is more than I normally throw. I started turning it up at the end and it still felt good."
Eyre has a "loose body" in his elbow, which caused him a sharp pain when he last pitched. He received a cortisone injection last week, and the Phillies had shut down Eyre to allow the shot to work.
"I honestly thought it was going to hurt," Eyre said. "I did. I just assumed it was going to hurt a lot."
Eyre will play catch again Wednesday from a longer distance and with more intensity, but the potential for problems will linger the rest of the season.
"It's all a matter of whether it floats into a spot where it's irritating stuff," Eyre said. "It moves around. I was on the computer last night and I went to pull my arm up and, 'Ow!' It still moves around in there. Just hope it's in a good spot."
The Phillies also said utility player Greg Dobbs would continue his rehab from a strained right calf with Class A Lakewood.
Lefty reliever J.C. Romero, who has been on the DL since July with a strained left forearm, is going to try to throw a bullpen session before the end of the homestand, the club said.
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.