WASHINGTON - Jeremy Guthrie tested his sore back by playing catch today, making 40 throws and expanding the distance to 90 feet.
Guthrie was diagnosed yesterday with a mild strain. He hopes to throw a bullpen session tomorrow and make Tuesday night's start in Pittsburgh.
"I'll see how my body feels, but tomorrow's my bullpen day," he said.
"It's improved. It's improved every day. I won't say it's completely gone, but it's improving every day."
Challenged to give reporters a percentage on how much his back has improved, Guthrie replied, "I don't know if I have the exact percentage. I'd say good to quite good is the best I can do. Good to quite good."
Meanwhile, second baseman Brian Roberts resumed his conditioning program yesterday after taking a few days off because of headaches. He still won't be cleared to begin baseball-related activities before being re-evaluated Tuesday by Dr. Michael Collins in Pittsburgh.