The 29-year old defender, who made over 100 league appearances for the Terrors at the beginning of his career, has joined the club until the end of January.
"Mark brings experience and ability to the squad. The short term deal will give him an opportunity to show there are no fitness concerns,” McNamara told the club’s official website.
"He will enhance our squad and his versatility is important. He is comfortable at right back and left back and also gives the option of playing in front of the back four.
"He is the type of player who will help us get control of the ball and settle us down when required and I am delighted he has signed."