And in this case, that's a good thing.
Webb threw 43 pitches in his fourth bullpen session of the spring on Sunday, once again mixing in some changeups and improving his mechanics.
"I think the velocity was better this time than it was last," Webb said. "I keep repeating myself, but I think it gets better every time."
That's music to the ears of the D-backs, who are counting on a healthy Webb to compete in the National League West. Last season, Webb made just one start due to shoulder issues that required surgery in August.
Conditions on Sunday were less than ideal. Rain and cold temperatures forced the D-backs to take batting practice inside and for Webb to throw his session in the team's covered batting cages at its Minor League complex.
There was not enough space in the cages for Webb to play long toss, which most pitchers do to warm up for a side session.
"Today was brutal," Webb said. "It was probably the worst day you could possibly throw. It was 42 or 44 degrees, it was wet, I didn't get to long toss. Under those circumstances, it was pretty good, productive."
Barring any setbacks, the plan is for Webb to throw one more bullpen session on Wednesday and then face hitters in a batting-practice setting once or twice. The team would like to get him into a Cactus League game around mid-March.
D-backs manager A.J. Hinch announced prior to the beginning of camp that Webb's first start of the regular season would be the third game of the opening series against the Padres at Chase Field.
"Starting in the middle of March would get me on time to do the third game of the season," Webb said. "As long as I can get five innings in my last start of Spring Training, I should be able to take that at least six innings in my first start, which is normally what we do. Not many pitchers go [complete game] out of the gate."
Mechanics are still an issue for Webb, who has struggled to get his arm up in the throwing slot quick enough from the windup. When he throws from the stretch, he is able to get the arm where he needs it to be.
On Sunday, Webb threw half of his pitches from the stretch and may have had a breakthrough with the mechanics.
"I feel like I sit down on my back leg for my load in the stretch and I don't do that in the windup," Webb said. "So in the last eight [throws], I went back from the stretch to the windup again and tried to feel like I was sitting down on my back leg, it was just a little bit, but I think there's something to that."
Facing hitters for the first time might also help the problem.
"Everybody keeps saying when you get hitters in there, you're going to lock yourself in, it will come," Webb said. "I'm anxious to do that."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.