For years, Villanova has had a "standing invitation" from the Big East to play football in the conference in which it competes in all other varsity sports.

But the Big East "officially informed us that its football schools were interested in adding Villanova as a football member of the Conference," Villanova president Peter Donahue said Friday in a letter to alumni.

What's the difference?

As the sands keep shifting in college sports, as conferences realign - adding or losing members, the Big East is trying to protect its flanks. The window is open for Villanova now, but it could close. The school is expected to give the conference an answer around the end of the year. If 'Nova decides to stay put in the Football Championship Subdivision (formerly Division I-AA), expect the Big East to look elsewhere for an extra member.

That suggests another wrinkle. Several college sources said that Temple, a former Big East football member before it was booted out of the league after the 2004 season, has been mentioned as a potential member now that the Owls are winning games in the Mid-American Conference. On Sept. 3, in the opener for Villanova and Temple, 32,000 fans saw the Owls beat the Wildcats in a last-minute, back-and-forth thriller.

The Big East would not be interested in both Villanova and Temple, those same college sources said. The Wildcats are at the plate now. The overture to Villanova, the defending FCS national champion, is considered a preventive move in case the Big East loses a member - if the Big Ten comes calling for Rutgers, for instance.

"It's the cleanest move," one Big East source said of taking Villanova.

Even if it doesn't lose a team, the Big East wouldn't mind adding a member. It's easier to schedule with a nine-team conference, with each school playing eight league opponents.

"I think we've done a great deal of homework on this," Villanova athletic director Vince Nicastro said. "You continue to cross-check all of your assumptions. I think most of the work will be packaging it and presenting, educating our trustees who will be making the decision."

A major issue is a playing field. Temple is in the eighth year of a 15-year lease at Lincoln Financial Field, so that doesn't appear to be a likely option. PPL Park, the new soccer stadium in Chester, could be viable. Franklin Field certainly would meet the criteria.

Radnor Township has never been receptive to enlarging Villanova Stadium or building another one on-campus.

"They made that clear this morning," said one Villanova source, reiterating that all options involve playing off-campus, while upgrading on-campus practice facilities.

A number of Villanova sources said it is difficult to forecast whether Villanova will take the leap to Division I-A. One source said Villanova spends about $5 million on football now, including scholarships, with about $1 million in revenues. Scholarships would go up from 63 to 85, with another 22 scholarships needing to be added to women's sports to meet Title IX requirements.

Big East schools "probably spend between $10 million and $15 million" on football but get most of that back from television revenues. Still, many of the conference football programs do not operate in the black, a Big East source said.

However, "the climate for television rights is really robust, despite the economy," one Villanova source said. That's what is driving a lot of the current timing, the source said, as the Big East looks to solidify its membership by the time a window opens to renegotiate a TV deal after the 2012 season.

A difficulty, several administrators said, is trying to predict what the landscape will look like in the future. Villanova does not want to be left out of a league that plays big-time basketball, which currently brings more TV money to Big East coffers than football does.

"Who knows what is going to take place between the time you say yes and the time you're actually there?" a Villanova source said of moving to Big East football. "You read the tea leaves, but in many ways you're looking at a crystal ball."