Rich Rodriguez and Scott Frost are new to the Big 12 Conference, but not to the schools that have welcomed them back.

Rodriguez at West Virginia and Frost at UCF are the only new coaches in the 16-team Big 12, and now have been through their first spring since getting back to their old schools.

West Virginia has gone through 13 seasons in the Big 12, but were still in the Big East when Rodriguez led the Mountaineers to three consecutive 11-win seasons from 2005-07 before his departure for Michigan.

Frost was the coach for UCF’s undefeated season out of the American Athletic Conference in 2017, when the Knights declared themselves national champions before he left for Nebraska.

Things did feel different for Frost than his first spring with the Knights in 2016, when they were coming off an 0-12 season.

“Our first scrimmage out here in the spring, I was discouraged coming off that field. ... We didn’t do anything good, or at least it felt that way,” Frost said, recalling 2016 before turning to this spring. “We’re doing some good things. There’s just a level of speed and precision to execution that has to happen on every single play to make it work, and we’re not there yet.”

The Knights were 10-15 in their first two Big 12 seasons under Gus Malzahn, the former national champion who left UCF after four seasons to become offensive coordinator at Florida State. The back-to-back losing records to open their Big 12 era followed a school-record six winning seasons in a row, which began with the 13-0 season after Frost’s 6-7 debut.

The second stint for Rodriguez at West Virginia comes 18 years after his first one ended. He will have to make wholesale changes in the name, image and likeness era — along with the transfer portal and pending roster limits — if the Mountaineers are going to compete for a Big 12 title.

The offense lost its entire line and top three receivers. Four receivers return who combined for 524 yards last season.

“We just don’t have enough for our system ... We just don’t have enough bodies,” Rodriguez said. “We want somebody obviously who can be that 1-on-1 guy that you can rely on. And our guys are getting better, getting some confidence in them. But we literally don’t have enough bodies to run the way we want to run it.”

Big 12 backs in the NFL draft

All five Big 12 running backs who averaged at least 100 yards per game last season were selected in last week’s NFL draft.

Only two of the top 10 rushers from last season are still in the league: Baylor’s Bryson Washington (1,028 yards, 12 touchdowns) and BYU’s LJ Martin (723 yards, 7 TDs).

West Virginia’s offense could revolve around running back Jahiem White, who had 845 yards rushing and averaged 6.5 yards per carry last season in a two-back system for the Mountaineers.

Dylan Edwards, now a junior at Kansas State, averaged 7.4 yards on his 74 carries last year behind drafted JD Giddens. Carson Hansen had 13 rushing TDs for Iowa State, the most for any Big 12 returning back.

All-everything RB Cam Skattebo is gone from reigning Big 12 champion Arizona State, which just added Kanye Udoh from the transfer portal after he ran for 1,117 yards and 10 TDs last season for Army.