MacDonald is expected to play in the Rugby World Cup

MacDonald, 26, was an ever-present in the Leeds team that secured promotion back to the Guinness Premiership last season, scoring 10 tries.

"I had a great time at the club last year and there is a great team spirit within the squad," he said.

"Like everyone else, we have got a point to prove next season and I'm looking forward to it."

MacDonald, who played two matches in the USA's recent Churchill Cup campaign, will link up with Leeds after the World Cup.

Director of rugby Stuart Lancaster said: "Mike was a key player for us throughout our National One campaign.

"He has proved to be an effective player, not just at scrummaging, but also as a ball carrier and a defender."