The Big 12 has a replacement lined up for Missouri before it even leaves the conference.

The Big East, meanwhile, is in danger of losing another school before replacing the three that already have bailed on the league.

Acting quickly to make sure it maintains a 10-member lineup, the Big 12 approved bringing in West Virginia to replace Missouri when the Tigers complete their move to the Southeastern Conference, a person with knowledge of the decision told The Associated Press on Tuesday.

The person spoke on condition of anonymity because the Big 12 had not announced that the conference board of directors on Monday unanimously approved inviting West Virginia when Missouri’s spot comes open.

The move is another step toward stabilizing a Big 12 that seemed on the verge of collapse about a month ago when Texas and Oklahoma were pondering a move to the Pac-12.

On the other side, West Virginia’s pending departure from the Big East, which has lost two members and one member-to-be in the last six weeks, leaves the embattled conference facing another crisis.

Because there is no timetable for Missouri to complete its expected departure from the Big 12 — and the league’s board of directors expressed “a strong desire” for Missouri to stay — there is no timetable for West Virginia to receive a formal invitation, the person said.

But West Virginia will accept an invitation from the Big 12 once it is offered, the person said.