Jorge Lorenzo has dismissed the notion that his decision to join Ducati from the end of this season was influenced by his shared status with team-mate Valentino Rossi within Yamaha.

The reigning MotoGP world champion said he was unconcerned that he was not the clear number one rider, adding that sharing top billing with Rossi was never an issue for him.

Lorenzo, though, admitted that one big draw in signing a two-year deal with Ducati was the extra input he will have in shaping the development of the Desmosedici.

"I was never worried about being the number one or number two, like I always said for me it was enough to have exactly the same parts or tools than my partner because I believe in my potential and for me that was enough," Lorenzo said.

"But of course it could be a different philosophy because Yamaha always make an evolution of the bike not only with the official riders but with the four riders of Yamaha, and probably in the future I will have more power to create more the bike I want to ride. They will hear me with more focus in myself."

The triple MotoGP champion, speaking at the official press conference ahead of this weekend's fourth round at Jerez in Spain, described his decision to leave Yamaha as one of the toughest he has ever had to make.

"It has been one of the most important and difficult decisions of my life, of my career, but at this moment it is still very far away, there is still 15 races remaining, so all my focus is on the present and on this championship," he said.

"I really want to fight to the end to win my fourth MotoGP world title, so at this moment I am just thinking in blue and I will try to get the best results in every race with this team and try to win the championship.

"Now all my future is solved and tomorrow is the Friday and if you don't have the mind really focused on a MotoGP it can be even dangerous, so I have to be focused to get the best result and it is still very far away to think about the next future."

Lorenzo reiterated that the key factor in his move to Ducati is to take on a new challenge and maintain his motivation at the highest level.

"I think [there are] many reasons, but the biggest one has been my motivation - the challenge to try to win with another bike and the challenge for me after so many years in MotoGP to keep my maximum effort every day," he said.

"I feel very grateful to Yamaha for all these years and especially with Lin [Jarvis] because he signed me when I was just 18-years-old and we won many world titles together. I think probably without Yamaha I wouldn't be three-time world champion of MotoGP and they mean a lot to me.

"The main thing is the motivation of a new challenge to work with another bike and to have this direction in my mind."

Looking ahead to this weekend's race in Spain, Lorenzo is confident he can claw back ground on Marc Marquez, who holds sway at the top by 21 points after the first three races.

"I started in the best way in the Qatar race and then everything got complicated with my crash in Argentina and it was a pity to lose so many points in this race," said Lorenzo, whose victory at Jerez last year was the catalyst for a four-race unbeaten streak.

"Luckily in Austin MotoGP we finished second in a race that a lot of riders crashed, so in this moment I am second in the championship and we have a really high chance to fight for it.

"I feel we have a higher potential than last year to win races. Marc and Honda are improving and coming stronger than they were in the pre-season but I feel strong here to fight for the victory and in the next Grand Prix."