It also might be the last time he does so while wearing an Arizona Diamondbacks uniform.
The right-hander threw two innings during an instructional league game against the Rockies, allowing three hits and two runs while striking out one. Webb had thrown two other times in instructional league games, but this was the first time he had gone two innings.
"It kind of went the way it's been going through the bullpen and [simulated] games," Webb said. "Once I sit down for a second and come back out, I end up feeling better. Even though I gave up a couple of runs, I ended up feeling better that second inning."
Webb's velocity is still not where it was before his shoulder surgery last August, though he did touch 85 mph at one point, a high-water mark for him during his rehab.
"The velocity will come," he said. "The time off will definitely be good for me, too, from that aspect. I'm still feeling a little bit for it when I go in to righties. I'm still a little cautious -- feel like I'm guiding it in there, trying to place it in there and not really letting the ball go like I should."
The next step for Webb is going to be a few months off. The free-agent-to-be will not start throwing again until January, and he will likely need to audition for teams before Spring Training.
"That will be good for me," Webb said of the break. "I've been going pretty much since the surgery last year non-stop. [I'm] a little bit tired. Even though I haven't been in the games, I've been doing stuff and throwing pretty much the whole time. I'm going to take some time off and then get going for Spring Training."
Webb was drafted by the D-backs, came up through their system and won the National League Cy Young Award in 2006, before injuring his shoulder on Opening Day of '09.
"It definitely could be," Webb said when asked if Thursday could be the last time he puts on a D-backs jersey.
"Obviously -- I've said all along -- hopefully not. This is the place I started and I love playing here. We'll have to see where it goes from here. This is the first place I'd like to play. I've loved every minute here. My wife and family love it here, too. It's been a great time, and hopefully it's not the last."
The man who will make that decision, new general manager Kevin Towers, was sitting in the stands watching Webb on Thursday.
"I haven't seen him live in a couple of years," said Towers, who was the Padres GM for 14 years before being dismissed near the end of last season.
"It looks like he's making progress every time that he's out there. It looked like the arm stroke was pretty good. The velocity is continuing to increase a little bit. It was nice to see him back on the mound again."
Towers was asked what it would take for him to offer Webb a contract to come back.
"Well, I think we have to look at the pool of players that are out there," he said. "As we approach the free-agency season, I think we need to weigh him compared to the people that are out there -- that will be available in the next month or so. Right now, I'm still evaluating front office, scouts and player development people."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.