Agar's decision to relinquish the position he has held for the past three years follows the Rhinos' 26-12 defeat away to Salford Red Devils in last Friday's Betfred Super League match which left them with just one win from their first six matches of the 2022 season.

The 50-year-old, who guided Leeds to Challenge Cup glory in 2020, will remain at Headingley in a role to be determined, while his assistant Jones-Buchanan steps up to take charge of the team for this Saturday's sixth-round Cup clash at home to Castleford Tigers with the help of Sean Long and performance director Richard Hunwicks.

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"When I first took on the head coach's job three years ago, I agreed with [then-director of rugby] Kevin Sinfield and [chief executive] Gary Hetherington that I would do so on the basis that I could help take the team forward," Agar said.

"I agreed a six-month rolling contract and I was happy to continue whilst we were making progress. However, I don't feel like I am having the impact I would hope to on the squad.

"I am proud of our record over the last three years. The club was in a tough position when I took over, we battled against relegation before facing the unprecedented challenges of Covid and an injury-ravaged squad last season.

"On the field, we won the Challenge Cup at Wembley, reached the play-offs in the last two seasons and saw the emergence of a number of highly promising young players.

"I really believe we have a strong squad who have the potential to achieve this year. They are working hard in training every day but unfortunately this has not materialised into results and ultimately that responsibility rests with me."

Former Hull FC and Wakefield Trinity head coach Agar joined the Rhinos in 2018, initially in a player development role, but was later put in charge of the first team on an interim basis followed David Furner's sacking just six months into his reign.

He subsequently took over the job on a full-time basis and oversaw a first Challenge Cup win for five years as Leeds edged out Salford 17-16 at Wembley in the pandemic-affected 2020 campaign, as well as guiding them to the Super League play-off semi-finals last year where they were beaten by eventual Grand Final winners St Helens.

But a tough start to the 2022 campaign has seen Agar decide to step down from the role, with seven-time Grand Final-winning former Leeds forward and Sky Sports rugby league pundit Buchanan now having a chance at the top job after joining the club's coaching staff following his retirement at the end of the 2019 season.

Rhinos chief executive Gary Hetherington has vowed the club will undergo a "comprehensive recruitment process" for a new head coach, but placed no timescale on the appointment of a permanent successor to Agar and thanked him for his efforts, with the focus now on Jones-Buchanan's first game in charge this weekend.

"Normally with teams in this position, it is easy to identify the causes of a down turn in form such as this but, in our case, it is a difficult one to solve," Hetherington said.

"The teams preparation has been good each week, the spirit within the group has been strong throughout and our coaches and backroom staff have worked tirelessly to provide our players with excellent support. We started the season with what we believed was a very strong squad with an outstanding crop of talented young players, but we have simply not converted that into team performances.

"This Saturday we entertain Castleford Tigers at Headingley and the Challenge Cup offers another opportunity to get our season started. All our focus will be on this game and then St Helens the following week as we return to Super League action.

"Jamie Jones-Buchanan is excited about his new opportunity and I am sure he will bring the same passion, enthusiasm and expertise to this new role as he showed throughout his playing career."