Boss Gerard Houllier gave McAllister a new lease of life in his late 30s when signing him for Liverpool. Now he has offered the same chance to former Arsenal player Pires, who has signed a six-month contract until the end of the season.
McAllister said: "He is a proven winner. It gets thrown around a lot these days when people say they are a winner but he is a genuine article.
"He's a European champion and he has won the World Cup as well. He has vast experience and was a fantastic player in the Premier League for Arsenal. People thought he was coming to the end of his career but he went to Villarreal and done well there for several seasons."
McAllister added: "For all the younger players - what a tremendous addition. The younger players can only learn from watching a guy like Robert on the training field. He will gain respect. But I am sure Robert Pires isn't coming here just to be a player that everyone is going to stand back and admire.
"He will want to gain the respect of the fact that he is still competitive and still able to do a job at this level."