Horner: Mercedes weaker without Niki directly involved

After undergoing a lung transplant during the summer of last year, Lauda has had small setbacks on his way to recovery and is likely to miss the first few races of the season, at least, as he works towards becoming fully fit and healthy again

In a wide-ranging interview with the Daily Mail, Horner spoke fondly of the three-time F1 World Champion, "Niki is a big force of nature. I hope he will be back soon. It is a tough thing he has had to go through, but he is a fighter. He is unbelievable."

Mercedes team principal Toto Wolff and Lauda is an admirable and effective partnership, the pair combining to sustain the Silver Arrows as the force to beat in the top flight.

Horner continued, "Looking in from the outside, Niki's absence is felt. You could see that with Toto at the end of last season when Niki was already away."

"Niki would be missed even more if it was a close fight for the title. He is always very good with the drivers and on big decisions. He was there partly as a crutch for Toto to lean on"

"Niki has a wealth of experience and was never afraid to voice an opinion. He had the trust and support of the Mercedes board as well. So the team will be weaker without Niki having a direct involvement for now."

Beating Mercedes on track is the goal of all the nine teams on the grid, the German team racking up ten titles in the past five years.

While Ferrari are sure to challenge, the jury is out on what Red Bull can do with Honda when the chips are down - we will know soon enough as the season kicks off this Friday in Melbourne.

Ahead of the season-opening Australian Grand Prix, Horner said of his team, 'There is a genuine feeling of optimism for a more competitive season than in recent years. Melbourne throws up strange results and it will take three races to get a clearer picture of how everyone stands."

"A three-way fight between Lewis, Sebastian and Max would be perfect, with the youngsters coming on strong from behind. It may come down to who can develop most efficiently right up until the first weekend of December and the last of the 21 races in Abu Dhabi. That would be great."

"Ferrari will come out of the blocks hard and I hope we're not far behind," added Horner whose team last won an F1 World Championship in 2013 with Vettel.