Orchard Park, N.Y. — Rex Ryan's first full day on the job as Buffalo Bills coach featured a much anticipated switch of coordinators.
Greg Roman was hired to run the offense, and Jim Schwartz is out as defensive coordinator in a pair of moves announced by the team Tuesday afternoon.
Both decisions did not come as a surprise under Ryan, who arrived in Buffalo earlier in the day.
Schwartz and Roman were among 12 candidates interviewed by the Bills to replace coach Doug Marrone, who stepped down abruptly on Dec. 31.
Schwartz is now free to pursue other jobs after his contract was terminated. The former Detroit Lions coach spent one season in Buffalo, where he played a significant role in helping the Bills' defense lead the NFL with 54 sacks, finish fourth in yards allowed and produce three Pro Bowl linemen.
Ryan is a defensive specialist, and has traditionally used an attacking three-lineman, four-linebacker alignment. That differs from Schwartz, who preferred going with a 4-3 alignment that didn't rely on much blitzing.
"I wanted to give Jim the opportunity to pursue other opportunities, and so we have terminated his contract," Ryan said in a statement released by the Bills. "He did a terrific job with the Bills defense this past year, and our plan is for our defense to continue to play well and be a dominating force."
Ryan, who was fired after six seasons with the New York Jets, is expected to hire a number of members of his former defensive staff, including coordinator Dennis Thurman.
The switch means the Bills defense will be led by a fifth coordinator in as many seasons.
Schwartz was highly popular among Bills players, including veteran tackle Kyle Williams.
Following the season, Williams said he intended to "chain (Schwartz) to a car in the parking lot" to prevent the coordinator from leaving.
As for Roman, he had been in talks to become the Bills offensive coordinator since Ryan tentatively agreed to a contract on Sunday.
Roman spent the previous four seasons serving as the San Francisco 49ers offensive coordinator. His status in San Francisco was uncertain after coach Jim Harbaugh left to coach Michigan.
Roman and Ryan share a similar run-first philosophy. In San Francisco, the 49ers running attack ranked in the NFL's top 10 in each of the past four seasons.
Roman and Ryan also previously worked together as assistants with the Baltimore Ravens in 2006 and 2007.
He replaces Nathaniel Hackett, who was not expected to be retained after two seasons in Buffalo. Hackett was one of a number of Marrone's assistants at Syracuse, who followed their coach to Buffalo in January 2013.
The Bills offense struggled under Hackett. After finishing 19th in the NFL in yards offense in 2013, Buffalo dropped to 26th this past season.
Ryan is scheduled to be formally introduced as the Bills coach during a news conference Wednesday.