The defender was initially offered the deal late last year but opted to bide his time before putting pen to paper.

However, with the 22-year-old having allowed his previous contract to run out, decision time has arrived.

The youngster made the breakthrough into the Boro first team back in 2004, but has been plagued by injuries ever since.

A broken leg last season ensured that he has spent the best part of three years on the sidelines, although he did make a eagerly-awaited comeback as a second half substitute in the 8-1 mauling of Manchester City in Boro's final game of the 2007/08 campaign.

McMahon is now hoping that his troubles are firmly behind him and is looking forward to the prospect of forcing his way into Gareth Southgate's plans next year.

"Being fit is a wonderful feeling after everything I've been through," he told the Evening Gazette. "I feel sharp and just want to stay fit.

"I'm already looking forward to next season and becoming an extra player for the manager to choose from.

"The gaffer has also been very supportive. He has been brilliant for me. For a long time when I was having treatment I was first in the car park at Rockliffe (training ground) and last out.

"It's a great feeling to be part of the first team scene again. A lot of people have occupied the right back spot since I was last playing regularly," he added. "Luke Young has done well and hasn't missed many games.

"But I'm determined to start giving him some competition. My career has been a bit of a rollercoaster so far, but I'm on the up at the moment and I am keen to keep it that way."