Michael Schumacher had many well-documented bust-ups with his Formula One teammates, but that has not stopped his former Ferrari co-driver Felipe Massa from praying daily for the stricken German.

Massa and Schumacher spent one season together at the Maranello team in 2006.

Speaking in Malaysia ahead of this weekend's Grand Prix, Massa expressed hope Schumacher could yet recover from devastating head injuries he sustained in a ski crash in France, late last year.

The 32-year-old said: "I pray every day for him and will never stop thinking of him until he is okay."

The Brazilian had his own brush with death when he was struck in the head by a flying spring at high speed during the Hungarian Grand Prix in 2009.

Massa's private prayers for Schumacher come in the week when the former chief doctor of Formula One warned to expect "really bad news" about the former world champion's condition.

Gary Hartstein said it was "less and less likely that Michael will emerge to any significant extent" and blamed doctors treating him at Grenoble hospital for "worsening the outcome".

The gloomy prognosis followed Lewis Hamilton's bizarre comments about Schumacher, who he claimed was in a coma "for a reason". Hamilton replaced Schumacher at Mercedes in 2012 following the seven-time world champion's second retirement from F1.

Schumacher was not always popular among other drivers because of his extreme competitiveness, even by Formula One's high standards.

Eddie Irvine, whom Massa replaced at Ferrari, said once of the German: "[He] has intimidated people for a long time but he got away with it because he was Michael Schumacher."

Rubens Barrichello was almost forced to crash into a wall by Schumacher during a scrap for top position at the 2010 Hungarian GP. The pair were previously teammates at Ferrari.

Elsewhere, Schumacher's former Benneton co-driver Johnnie Herbert once complained Schumacher was obsessed about beating him in any contest, even ping pong.