BYU football coach Kalani Sitake’s rebuilding of his offensive coaching staff officially began Thursday morning with the announcement from the school that the Cougars have hired LSU offensive line coach and running game coordinator Jeff Grimes as their new offensive coordinator.

Grimes, who was BYU’s offensive line coach from 2004 to 2006, replaces Ty Detmer, BYU’s offensive coordinator in Sitake’s first two seasons.

“Jeff has great leadership ability and outstanding experience mentoring young men at the highest levels of college football,” Sitake said in a release. “He has vast experience working with exceptional coaches and programs during his career, including here at BYU, and we welcome his return to Provo to oversee our offense.”

Sitake said changes were needed when he released Detmer on Nov. 27. The BYU offense ranked among the worst in the country in 2017, and the Cougars went 4-9, suffering their first losing season since 2004.

Grimes, 49, was making $560,000 plus incentives at LSU. His salary at BYU is unknown, and the private school does not have to disclose it. But a source told The Salt Lake Tribune that it is “significantly” higher than what Detmer was paid.

Grimes is a 25-year coaching veteran and has spent 10 of those years as a running game coordinator. He never has been a play-caller. He was at LSU the past four seasons, and his replacement reportedly already has been hired, signifying that his hiring at BYU has been in the works for quite some time.

“I am so grateful for the opportunity to work, once again, at BYU,” Grimes said in the BYU release. “It is a special place, filled with extraordinary people and a rich football tradition.

“I recognize that with this position comes a great deal of responsibility to all of Cougar Nation. I not only welcome this, but consider it a privilege. My family and I are looking forward to returning to Utah and are ripe with anticipation for many great Saturdays in the fall in LaVell Edwards Stadium.”

Grimes thanked Sitake, BYU athletic director Tom Holmoe, school president Kevin Worthen and vice president Matthew Richardson “for having faith in me and granting me this opportunity.”

He also has worked at Virginia Tech, Colorado, Arizona State, Auburn, Boise State, Texas A&M and Rice. He was on the Auburn staff in 2010 when it won the BCS national championship game.

Grimes coached several of the best BYU linemen in school history during his three previous years in Provo, including Ray Feinga, Scott Young, Dallas Reynolds, Travis Bright and Lance Reynolds Jr.

The Cougars were No. 5 in total offense and scoring offense in 2006 and No. 13 in total offense and No. 24 in scoring offense in 2005. He left BYU after the 2006 season, Bronco Mendenhall’s second, to take a position at Colorado.

He helped developed star running back Leonard Fournette at LSU. His offensive line paved the way for four straight 1,000-yard rushers in each of his four seasons at the SEC school.

Grimes is from Garland, Texas, and was a four-year letterwinner at UTEP as an offensive tackle. He and his wife, Sheri, have four children.

BYU’s release said one of Grimes’ first duties will be completing his offensive staff for the Cougars, meaning that offensive line coach Mike Empey, running backs coach Reno Mahe, receivers coach Ben Cahoon and tight ends coach Steve Clark could be retained or released.

It appears that all of BYU’s defensive coaches’ jobs are safe.