Parker has become an integral part of Fulham's midfield since joining from Tottenham in August and Jol is delighted with his influence.
"He is a leader," said the Fulham manager. "Of course, there are other experienced players but I am very happy with his influence.
"Scott comes from another club and he tells the players if we are doing okay, or if we need more goals, or to be a bit more clever. That is what he adds to us."