FAYETTEVILLE — Bret Bielema had trouble retaining assistant coaches while at Wisconsin, watching several move on to promotions, lateral jobs or pay raises.

It’s one big reason Bielema left the Badgers in Dec. 2012, looking for a destination that could offer more money for coaches in hopes of staving off turnover on an annual basis. But it’s not exactly playing out like Bielema imagined at Arkansas.

Defensive coordinator Chris Ash is leaving the Razorbacks to become the co-defensive coordinator at Ohio State. Sports Illustrated was the first to report the move, citing a source as saying the deal was finalized Tuesday morning and the Buckeyes were expected to announce Ash’s addition later this week.

Bielema was not available for comment, but responded to the departure on Twitter.

"Have always felt transition on my staff has allowed us to get even better. Have had success hiring right people and will again. #woopig #1-0," Bielema said.

Ash has been a part of Bielema’s staffs at Arkansas and Wisconsin for the past four seasons. He has been Bielema’s defensive coordinator the past three years.

The Razorbacks struggled in 2013, finishing 12th in the SEC in points allowed (30.8 a game) and ninth in total defense (413.4). Personnel issues were the biggest flaws. Bielema said last month said Arkansas needed to rectify the problems in recruiting.

"There’s no doubt we need more skill," Bielema said. "We need more linebackers that can come in and play on an SEC type level. I think that the attitude was great. The intensity. Their preparation was good. But they just need to have better skill."

Ash won’t be around to lead the way any on defense any longer, though, returning to the Big Ten after a one-year absence. He will join Luke Fickell as Ohio State’s co-defensive coordinator and work for Urban Meyer.

Ash also became the second former Wisconsin defensive assistant to leave Arkansas this offseason. Defensive line coach Charlie Partridge was named the head coach at Florida Atlantic and has been replaced by Rory Segrest on Arkansas’ staff.

Ash earned $550,000 annually under the terms of his Arkansas contract, which was scheduled to run through June 30, 2015. The contract includes a $100,000 buyout, which is prorated over the length of the agreement to cover an early departure.

He is the third assistant to leave Arkansas for another position since Bielema was hired in Dec. 2012, joining Partridge and George McDonald (Syracuse offensive coordinator). The next defensive coordinator will be Arkansas’ fourth in four years, following Willy Robinson (2011), Paul Haynes (2012) and Ash.

"Very happy for former coaches that decide to move to new challenges, the respect our staff gets nationally will continue to grow," Bielema also said via Twitter.

It’s not immediately clear which direction Bielema will turn for his next defensive coordinator, although FootballScoop.com reported that former Tampa Bay Bucs linebackers coach Robb Smith could be the pick. Smith, who had defensive coordinator stints at Rutgers (2012) and Maine (2006-08), was at Iowa from 1999-2001 when Bielema worked as the program’s linebackers coach.

Bielema also has an experienced defensive coordinator on his current staff in linebackers coach Randy Shannon. Shannon was Miami’s defensive coordinator from 2001-06 before being elevated to head coach in 2007.