Nine-time world champion Valentino Rossi believes his Factory Yamaha team-mate Jorge Lorenzo is still 'the best' rider in MotoGP despite Marc Marquez's record-breaking title success in 2013.

Rossi, who earned a single race victory at Assen this year following his eagerly anticipated reunion with the YZR-M1 in the wake of a troubled spell at Ducati, heaped praise on his old sparring partner, who took the championship fight with Marquez down to the wire.

The Italian great and Lorenzo clashed during Rossi's previous stint at Yamaha in 2010, but 'The Doctor' says a greater rapport existed between the pair this season.

"Sincerely, the atmosphere this year was very good and so was the relationship between Jorge and I. He is one of the best... for me, now, he is the best," Rossi told the official MotoGP website.

"This year he did something great, even though he didn't win the championship, so I am very happy to be in the same team. It is always a great fight and it is always great to try and raise our level.

"I would like to say that it was a very good season with a lot of good races, but we did indeed have some highs and lows.

"This year was difficult, for sure, and at the end of the season I had hoped to be more competitive and to be fighting for podiums. Unfortunately, sometimes we pushed too hard and I wasn't able to, but we will try again next year.

"First of all, we will now relax and recharge the batteries to be ready for next year. The target is to try and do better: try to be on the podium more, try to win some races and see where we are at the end of the season."

Rossi also responded to recent speculation surrounding his retirement from MotoGP and reiterated his desire to continue for another two years in the class after next season.

"It was very clear, but they put the news in the right way to [create] some rumours," he said.

"I have another year of contract and in my heart I want to continue after next year, with another contract of two years, but I have to be competitive, so I will decide next year."

In terms of his hopes for 2014, Rossi - who has parted company with long-serving crew chief Jerry Burgess and teamed up with Silvano Galbusera - says he wants the Yamaha M1 to be adapted further to suit his riding style.

"This is the target with Yamaha and they also have a lot of motivation to try their best for me to be able to try and stay at the front. I can't wait," he said.

"We will see, but that is the target: to improve the bike and make it more suitable for me."