The 35-year-old was suspended, for the first time since 2009, following a challenge on Leigh Centurions centre Greg Worthington in Rhinos’ final game of the season last Thursday.
He was sin-binned following the incident and charged with making grade B dangerous contact by the RFL’s match review panel.
The governing body’s disciplinary committee later banned him for two games at a hearing this week.
The Leeds man was unable to attend the hearing due to a previously arranged church event, but wrote to the panel to express his regret.
In the letter, he apologised for his absence and added: “In regards the offence for which I am charged, I must again send my ‘sincere apologies’ for a tackle that was both desperate and poorly executed.
“That type of tackle is not what we practice nor endorse at the club. I accept that in a reckless moment of desperation, I have contributed to the injury of another player.
“This season I would have been involved in circa 800 tackles and got this one terribly wrong by the standards for which I aim. This was on my mind for much of the remainder of the game - please refer to the Sky Sports interview where I apologised immediately after the game during an interview with Barrie McDermott. I did also speak to the Leigh player in question after the game and apologised to him also.
“However, I understand that action needs to be taken to ensure dangerous tackles don’t creep into the game, so I humbly accept any disciplinary action that the panel deems fit.”
The suspension will be served in pre-season, so Jones-Buchanan will be available for Rhinos’ opening Super League game next year.
Worthington, a former Featherstone Rovers player, suffered a medial knee ligament injury, but is expected to be fit for the start of next season.
Meanwhile, former Rhinos hooker Robbie Ward has signed for Dewsbury Rams following a spell with Featherstone this year.