"This time I felt ... not hesitant, but the residual effects from the first time out," said Johnson, who underwent back surgery last October. "Back was a little stiff, legs were a little stiff."
After his first 15 to 20 pitches, he set down his glove, took a drink of water and stretched his back just a bit before getting back up on the mound and finishing the session strong. He wound up throwing 37 total pitches, all fastballs, from both the windup and stretch.
"I thought the second 17 pitches were much better, so I ended on a good note," he said.
When Johnson was done throwing, he went through a series of agility drills before moving on to a weight room session.
Non-roster invitee Mark Johnson caught Johnson's session, which was observed by manager Bob Melvin, pitching coach Bryan Price and pitching adviser Mel Stottlemyre, among others.
"Maybe the first few weren't as fluid as the first time out," Melvin said. "The second round was a lot better. That's to be expected, especially after the first time on the mound. The last 15 were outstanding."
The initial stiffness was typical of a pitcher, whether he's coming off surgery or not, after he throws for the first time during the spring. Johnson will take the next two days off, and unless he experiences a setback, he'll be back on the mound for another side session on Thursday, when he'll throw 35 to 45 pitches.
If all goes well, he'll throw his fourth bullpen session on Sunday, then he and the coaching and medical staffs will map out a future plan.
"So I've got basically two more side sessions, or two more mound sessions of hopefully 35 to 45 both times, and then just see where I'm at by the end of the week," Johnson said. "I'd love to get out there and throw some batting practice now, but I think it's a situation where I need to work up to it at this point."
Ouch: Reliever Brandon Medders has been experiencing some tenderness in his right elbow, but said that during his throwing session on Monday, he felt the best he has all spring.
"I don't know what changed, but I felt really good today," Medders said. "The guys in the training room have worked hard on me. I haven't missed a throwing session yet. [The doctors] said it's in an area [of the elbow] that's less serious, so that's a good thing."
Feeling better: Outfielder Scott Hairston, who was struck on the right elbow by a Chris Snyder line drive on Saturday, said that his condition had improved on Monday as he played catch and also swung the bat.
"So he's on schedule to do everything full up [on Tuesday], and then will be in the intrasquad game the next day," Melvin said.
Meeting time: Union chief Donald Fehr met with the players prior to Monday's workout for his annual state of the union address.
"Things have been going pretty well and that's one of the things we've been telling the positions," Fehr said.
D-backs player rep Conor Jackson said that the meeting had a different feel than last year's, which came as the owners and players were gearing up for talks on a new basic agreement.
"It went [well]," Jackson said. "There were a lot of things discussed. It's a real peaceful situation right now [between the owners and players], so it wasn't like last year, where we didn't know what was going to happen and everything was kind of up in the air. This year was more of an overview of what happened, how we went about things and how everything turned out good."
Up close and personal: Last year's Cy Young Award winner, Brandon Webb, threw batting practice on Monday to some of the camp's younger players.
"They found out what Webb's sinker is all about, even the lefties," Melvin said. "Webby is going to do his thing. You can watch him on TV, but until you actually stand up in there in the box and see that thing coming in, you just don't get the full effect of it. He was on top of his game over there."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.