Former Australia A flanker Mitchell Chapman has joined the Waratahs for the 2013 season.
He has signed on a one-year contract, replacing injured hooker Damien Fitzpatrick, who has been ruled out for the season.
The injury is a cruel blow for promising young hooker Fitzpatrick, who had been due to return to action next month after a 12-month absence.
Meanwhile, Cheika opted against a like-for-like replacement as he already has three hookers at his disposal (John Ulugia and Tatafu Polota-Nau in the main squad and Luke Holmes in the Extended Playing Squad). He added: "Mitchell has been brought in to fill a specific profile within our squad.
"I felt we needed a lock who will be able to help share the workload of our two internationals, Kane Douglas and Sita Timani, and offer an experienced partner for our two young locks, Ollie Atkins and Greg Peterson, especially around the set piece.
"I was convinced of this idea when I spoke to Mitch and saw his enthusiasm for another shot at playing Super Rugby. He seems a quality person and I believe he will fit in to our team environment very well."
The 29-year-old blindside specialist returns to Australian rugby following the completion of his second season with Japan Top League club NTT Docomo.
Having made 28 appearances for the Reds and 40 for the Brumbies, he brings extensive Super Rugby experience and is excited about returning to Super Rugby. Chapman added: "I've been watching it on TV and the chance to come back and test myself against the best players has been very motivating.
"Specifically with the Waratahs, I know some of the things that Michael Cheika has put in place rugby-wise. Through the grapevine I've also heard that it's a positive place to be. Along with how they are looking to play the game, that was something I wanted to be a part of and the main reason for my decision."