PHOENIX -- With just over a week until Opening Day, decision time is looming on the 25-man roster.

While it would seem like the D-backs' roster is pretty well set, manager Kirk Gibson said not so fast.

"I have, probably, in my mind a pretty good idea," Gibson said. "But there's more to be resolved in my mind, as well. You want to make sure that you let that unfold."

It was similar to the comments that Gibson made on Tuesday, when it was suggested that young left-hander Patrick Corbin, who has had an impressive spring, would begin the year in the Minors.

"You're assuming that's where he's going," Gibson said. "There are some things that still could happen."

On Wednesday, Gibson and general manager Kevin Towers led a discussion on the roster. Gibson asks for input regularly from his coaching staff.

"We had discussions today about when and who," Gibson said of upcoming cuts. "I might see it one way, KT might see it another way, [first-base coach] Eric Young might see it another way. We want input."

Gibson said that he was unsure what the timetable was for the next round of roster moves.

The starting rotation is set with Ian Kennedy, Daniel Hudson, Josh Collmenter, Trevor Cahill and Joe Saunders.

The seven spots in the bullpen seem to be spoken for as well in J.J. Putz, David Hernandez, Bryan Shaw, Brad Ziegler, Takashi Saito, Craig Breslow and Joe Paterson.

The only way Corbin would seemingly be able to make the team is if one of the above pitchers were to get hurt of if the D-backs were to make a trade.

The far safer play is to have Corbin begin the year in the Minors as a starting pitcher and be ready to come up should one of the other pitchers falter. If he were to start the year in the 'pen, then it would take time to stretch him back out as a starter.

Another tough decision involves left-hander Mike Zagurski. He has pitched well this spring, but with Breslow and Paterson in the bullpen, there seems to be no room for him. Zagurski is out of options, and getting a left-hander through waivers, especially one throwing well, is not likely.

The position-player side of the roster has seemed to be set ever since it became clear that shortstop Stephen Drew would begin the year on the disabled list.

By all accounts the starting lineup will include Jason Kubel, Chris Young, Justin Upton, Ryan Roberts, Willie Bloomquist, Aaron Hill, Paul Goldschmidt and Miguel Montero.

In addition to the starting lineup, the bench spots will likely be filled by Geoff Blum, Henry Blanco, John McDonalds and Gerardo Parra.

Gibson has surprised in the past, and whether the club is working on a potential trade is not known.

"There's various things that could happen," Gibson said.