The Cincinnati Bengals re-signed long-time head coach Marvin Lewis to a two-year contract through the 2019 season.
However, defensive co-ordinator Paul Guenther will leave the team to pursue other opportunities, according to multiple media reports.
Lewis has won a franchise-high 125 victories during 15 seasons with the Bengals, but there was recent speculation that he might not return.
That was put to rest with the extension.
"Marvin Lewis has been an important member of the Cincinnati community and the Bengals family for the past 15 years, and we are happy to have reached this agreement," Bengals president Mike Brown said in a statement.
"Marvin has made significant contributions during his time here. While recently we have fallen short of our expectations, we have full confidence in Marvin to re-establish winning football in 2018."
Lewis and the Bengals have experienced back-to-back losing campaigns -- Cincinnati were 7-9 this season -- after winning 10 or more games in each of the previous four seasons and making the playoffs in five consecutive years.
"My family and I are very grateful for the opportunity to stay in Cincinnati and continue my career with the Bengals," Lewis said in a statement.
"My job is to win a World Championship. We have a talented roster full of veteran leaders and emerging young stars, and I am committed to making the necessary improvements to put this team in the best position to win."
The Bengals have been to the playoffs seven times during Lewis' tenure and haven't won a single playoff game.
Lewis, 59, was NFL Coach of the Year in 2009 when Cincinnati went 10-6. His overall record is 125-112-3.
ESPN reported that Lewis was leaning toward leaving the Bengals in mid-December, but Lewis repeatedly denied the report.
Like Lewis, Cincinnati's assistant coaches entered the 2017 season in the final year of their contracts, making them free agents at season's end.
Guenther, Bengals' defensive coordinator since 2014, was considered a potential candidate to be the next head coach if Lewis did not return.
ESPN reported earlier this week that Guenther is Jon Gruden's top choice to be the Oakland Raiders' defensive co-ordinator once Gruden is named head coach by his former team, which is expected.
Guenther has ties to Jay Gruden, Jon's brother and head coach of the Washington Redskins, as the two were on the Bengals' staff together from 2011 to 2013. According to multiple reports, Jay Gruden hoped to hire Guenther as Washington's defensive coordinator last offseason, but Cincinnati did not give the Redskins permission to interview Guenther.
The Bengals finished 12th, second and eighth, respectively, in points allowed over Guenther's first three seasons as co-ordinator, but they slipped to 16th in 2017.