The ex-Newcastle skipper who joined the club back in 1983 says he has experience in management with West Ham United, Watford and Gillingham and is not "frightened" of the job.
Roeder: "Without doubt the fans can help. I've always felt they were the 12th man and hopefully they will be with us, be very vocal and give the players the lift they need.
"All our thoughts and all our energies will be directed at beating Portsmouth. All we can do is gather ourselves this morning and go and pick a team that can beat Portsmouth. It won't be easy but we will lift our spirits and be very positive about the whole thing."
The 50-year-old has been out of management since August 2003. He endured a difficult time at Upton Park both on and off the field, missing the final weeks of the 2002-3 season after suffering a brain tumour.
Roeder made 193 league appearances for Newcastle between 1983 and 1989 and also enjoyed spells at Gillingham, Leyton Orient, Watford, Notts County and Queens Park Rangers. He was part of England's coaching staff at the 1998 World Cup.