Former F1 driver Juan Pablo Montoya said: "Micheal Schumacher is the missing link at Ferrari".Schumacher, the seven time World champion, remains in a critical condition following a skiing incident in December 2013.Montoya raced in Nascar after leaving F1 and will return to the Indycar series in 2014.'COMPETITOR NOT A FRIEND'Montoya said: "We spoke once in the six years that we raced against each other. He was a competitor, not a friend. As a McLaren driver I couldn't just go and sit in the Ferrari motor home."The only time Ferrari did well was when Michael was there."Similarly, he said Mercedes was to blame for Schumacher's unsuccessfull return. Montoya said: "He didn't forget how to drive. It's how it has always been in F1."He said it is difficult to comment on the current state of the sport, as "For seven years I haven't watched F1. Maybe one or two races a year."Latest on Micheal Schumacher.Stay with Wheels24 for the 2014 F1 season – fresh reports every day.