[5] In September 2011 it was announced that Agar had signed a three-year deal with Wakefield Trinity Wildcats, and would become their head coach following the end of the 2011 season.

[8][9] On 10 June 2014, it was confirmed Agar would become first team coach of Warrington Wolves for the 2015 Super League season working alongside Tony Smith.

It is believed he left because new Fédération Française de Rugby à XIII president Marc Palanques wanted a Frenchman to coach the national team.

[11] On 17 October 2020, he coached Leeds in the 2020 Challenge Cup Final victory over Salford at Wembley Stadium.

[12] In the 2021 Super League season, he guided Leeds to a fifth-placed finish on the table as the club qualified for the playoffs.