"It's getting fairly obvious that it's going to be difficult to get him ready for the season," Hinch said. "But I don't think we're at that date yet. We're getting to the point of where we're going to need to address that. Is it a couple of days away? Probably, but I'd like to see what he looks like next on the mound because you never know once he gets back on the mound if we can speed things up as much as we've slowed it down the last week."
Since saying last week that he felt "stagnant" in his rehab, Webb has played long toss and catch, but has not thrown off a mound. Wednesday in Glendale, he played catch and briefly threw a flat-ground bullpen session.
"I do know that he felt the best he's felt all camp yesterday which is a good sign," Hinch said.
Webb and Hinch both have grown tired of the continual questions regarding whether Webb would be on the active roster at the start of the regular season. The right-hander made one appearance last season before being beset by shoulder problems that resulted in an August surgery.
Webb threw off a mound for the first time in January and seemed to be on target for starting the season healthy when Spring Training opened.
However, the right-hander struggled initially with mechanical issues after not being on a mound for 11 months and most recently has had trouble letting it go and throwing with his full velocity.
Webb was given a complete day off Thursday and will play long toss Friday. If all goes well, they could have him throw a flat-ground bullpen session.
"Just because he's delayed or we had to take a little bit of a stop, it doesn't mean that he's shut down," Hinch said. "He's throwing. You never know when it's going to click for him and he's going to feel better. This might be all he needed, a couple-of-day breather."
"We are running out of time so it's important that we continue to inch forward," Hinch said. "But running out of time doesn't make the start of the season a failure, it just means we're moving at a pace where we're keeping him healthy and that he will maintain his health along the way."
Much has been made that it would be hard for the D-backs to have a successful season if Webb is not healthy and able to take the ball every fifth day, but Hinch said the presence of Edwin Jackson along with Dan Haren at the top of the rotation was "comforting."
Heading into camp, the rotation was slated to be Haren, Jackson, Webb and Ian Kennedy, with Billy Buckner the leading candidate for the fifth spot.
Thanks to early off-days, the D-backs could go until April 17 without needing to use a fifth starter. So if Webb is delayed by only a couple of weeks, it's possible they would not need another pitcher to fill his spot.
There's a very real possibility that they open the season with four starters and maybe an extra bullpen guy, or an extra position player, but that will all be decided the last week.
If they do need to replace Webb, they would likely need to pick two pitchers from among the group currently competing for the fifth spot. That includes Buckner, Rodrigo Lopez, Kevin Mulvey and Bryan Augenstein.
It seems unlikely the D-backs would be able to add a free agent at this point after having already surpassed their budget for 2010 by signing first baseman Adam LaRoche in January.
Arizona GM Josh Byrnes, however, has shown a willingness to pluck a player from the waiver wire particularly during Spring Training.
"The guys that we have there competing for these jobs are equipped to be Major League starters," Hinch said. "If Josh feels we can find something that can help our team in any position, he's shown over my time with him not to be a stagnant GM."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.