COLUMBUS, Ohio -- When the Big Ten and Pac-12 announced their partnership in December, they targeted 2017 as the first season of head-to-head play in football.

But the nature of nonconference scheduling and the needs of 24 different schools could result in a staggered start. Wisconsin athletic director Barry Alvarez told Brian Bennett that some Pac-12 schools are "dragging their feet a little bit" in relation to football scheduling, citing the difficulty of a slate featuring nine league games, a Big Ten opponent and, for some teams, another major-conference opponent.

There are also obstacles in the Big Ten. Ohio State athletic director Gene Smith told ESPN.com that the Buckeyes aren't scheduled to begin the Pac-12 partnership in football until the 2018 season.

The reason: Ohio State already has nonconference games scheduled against Oklahoma (home) and North Carolina (road) in 2017.

"I'm not taking [a Pac-12 game]," Smith said. "We can't start in '17, so we will start in '18."

Big Ten commissioner Jim Delany on Thursday issued a statement to ESPN.com that reads in part: "Both conferences reaffirmed plans to play an annual 12 interconference game football schedule beginning in 2017, subject to previously contracted non-conference games." The key line there is subject to previously contracted nonconference games. The way scheduling works, many schools have contracts out to 2017 and beyond.

Big Ten spokesman Scott Chipman on Friday told ESPN.com that the two conferences still have 2017 as the desired start date for all 12 football games. There's a chance teams could move around dates of games, which happens quite often. Michigan State recently added a home-and-home series against Oregon -- not part of the Big Ten/Pac-12 partnership -- because West Virginia had to get out of a series with the Spartans as part of its move to the Big 12.

Bottom line: both sides want an agreement, but there are a lot of moving parts (i.e. signed contracts with other teams). A lot could change before 2017, and the discussions will continue next month when the Big Ten athletic directors have their spring meeting in Chicago.

"It's more an issue of when we start," Smith said. "Is it '17 or '18, or is it '17 with some schools phasing in in '18 and '19? It's going to happen. It's just a matter of will it be just like we felt it was going to be at the beginning. Everybody's committed to making it happen."