"It was a bad day today," Jones said. "I didn't feel good doing anything. ... Some days I wake up and I can tell it's going to be a good day, and other days I'm going to have to fight my way through it."
Jones battled through the discomfort throughout most of Saturday's three-hour workout. In hindsight, he wishes that he would have skipped some of the drills that proved more demanding on his knee.
But because this was the first day the club was working on new manager Fredi Gonzalez's bunt defense and defensive fundamentals, the 38-year-old felt that he needed to remain on the field.
"I didn't do everything today," Jones said, "but I still went out there and got my reps in for three hours. The good thing is, I haven't had two bad days in a row. Hopefully, I don't start now.
"It's going to happen. I just don't want to pile days on top of each other where I can't get in shape or get my reps in. It might keep me from doing my conditioning. But it's not going to keep me from doing my reps -- hitting, fielding, throwing."
Jones might have brought on the discomfort by running the bases for the first time during Friday's workout. He also felt some pain on Tuesday while taking grounders and doing some other defensive drills for the first time since his left ACL was surgically repaired in August, for the second time (the first time was in 1994).
As he prepares for his 18th Major League season, Jones knows he is facing a challenge.
"I don't perceive there being any long-term problems," he said. "You work your way through the rough days and [I'll] get off it tonight, and tomorrow will be a little better."