The Big 12 also could add WVU and Louisville and either keep Missouri or add another school to get to 12 schools.
Some media outlets were reporting that Notre Dame might be in the picture as a 12th member, although not for football.
There have been reservations in the conference about expanding to 12 teams and thinning the revenue shares. A conference championship football game with 12 teams involved could add an obstacle to teams chasing a national championship.
However, if the Big 12 were definitely adding WVU and not considering a replacement, there would have been no need to cancel Wednesday's planned press conference.
WVU sources remained hopeful that the delay did not mean their Big 12 association was off.
Earlier on Tuesday the deal had seemed certain.
Several sources on both sides of the negotiations said Tuesday and again Wednesday that the Mountaineers and the Big 12 negotiated a deal over the weekend and finalized it Tuesday.
The snag occurred Tuesday evening and a few hours later the university released a statement.
"Contrary to media reports, there is no press conference scheduled for Wednesday concerning WVU's athletic conference affiliation. There are no further comments at this time," it read.
Multiple media outlets said Big 12 representatives were expected on campus and a press conference was being planned to officially announce the union with WVU.
Chuck Neinas, the Big 12's deputy commissioner, also told members of the conference office the league would be on WVU's campus Wednesday for an announcement. Luck met with WVU staffers Tuesday and told the group the Mountaineers were headed to the Big 12.
Both the school and conference were planning a press conference for 3 p.m. Wednesday, and the Big 12 office was preparing an official statement, one source said Wednesday.
Then, about 5 p.m. Tuesday, only a few hours after WVU believed it had finally completed the arrangement, the situation changed without explanation.
One person familiar with the development likened it to "crossing the finish line and then being pulled back across it - an hour later."
Contact sportswriter Mike Casazza at mi...@dailymail.com or 304-319-1142.