Roy Keane says he's eager for the challenge after becoming Martin O'Neill's assistant manager at Nottingham Forest.
The Irishman made over 100 appearances for Forest at the start of his playing career and worked with O'Neill when they led the Republic of Ireland into the Euro 2016 finals.
And he's delighted to once again pair up with the new Reds boss.
He said: "I am happy to be back. I know the manager, he came in a few weeks ago and things moved pretty quickly over the weekend. It is nice to get the deal done and get involved this morning with the first session.
"I am looking forward to it, it is a big challenge and I am ready for it.
"It is good to be back and it will probably take a couple of days to get back in the swing of things. Obviously, I had great memories of my career here as a player, the club gave me my chance and I will always remember them for that.
"But it is a different challenge now and I am in a different position coaching the players. I am looking forward to it, a huge challenge ahead and 20 years out of the Premier League. It will be tough but I am looking forward to it."
Keane said he is looking forward to working alongside O'Neill again as Forest aim to push for promotion.
He said: "There are a lot of big clubs in the Championship fighting to get out of it. When Martin got the job and gave me a shout, I thought that once a few things fell into place I'd be ready for it.
"We will give it a good go, I have huge respect for Martin and the club and it fell into place nicely. I have seen the team a number of times over the last year or two and it is going to be tough but hopefully, with one or two signings, a bit of luck we can hopefully be competing."