All Whites legend Nelsen may be thrust into action at Wembley just three months after his release from Blackburn..
He said: "I've played them (Chelsea) for the last eight seasons, we've all played against them..
"That's why I was brought in, to help out if situations arise like that, of course..
"We've got a squad of 25, every one of them will be needed at some stage in the rest of the season. It's really important and I'm looking forward to it."
When quizzed about the fear of facing the likes of Juan Mata, Didier Drogba and Fernando Torres, the New Zealand captain replied: "Well, they will be facing (Emmanuel) Adebayor, (Jermain) Defoe and (Louis) Saha, (Luka) Modric and (Rafael) van der Vaart.. We all see what they can do every day in training."