Pol Espargaro concedes he is walking into the unknown following his final race on the Monster Tech 3 Yamaha.

Espargaro finished sixth after a battle with his brother Aleix and Ducati rider Andrea Dovizioso at Valencia in Spain as the 2016 MotoGP World Champion concluded on Sunday.

The Spaniard will now become a factory KTM rider with Bradley Smith and Espargaro admits he is apprehensive over his decision to join the Austrian manufacturer after three years at Tech 3.

"It feels so strange, not bad, not good, because it is my last time I am wearing black and it is the first time in my life I am with the same team for three years," he said.

"I feel sad, but also I'm looking forward to jumping on the KTM on Tuesday but at the same time I'm a little bit scared because I am wondering what is going to happen, or what would happen if I stayed here one more year. The one thing is that the choice is gone already, so there is just one way - not coming back - so we will see.

"The good thing at Yamaha Tech 3 is that we always have a good base; we start the weekend and we are always there, always fighting for the top ten. The bad thing is we cannot improve. We are in top ten and we finish in the top ten, we don't improve to top five," added Espargaro, who will test the RC16 on Tuesday and Wednesday during the official test at the Ricardo Tormo circuit.

"These are the good things and bad things. The bad thing for KTM is that we will not start in the top ten, but maybe in the future we will be in top five.

"Nobody knows, but sometimes you make a choice and bet, and we have bet, so let's see. We will test everything and we have a lot of things to test. We will be like test mice! I need to understand what we can do and improve but already in the qualifying [Mika] Kallio surprised me because '32.0 is a good lap time."

Espargaro got the better of his brother and Ecstar Suzuki rider Aleix as they battled it out on Sunday, with Dovizioso eventually splitting the pair on the Desmosedici GP16.

"I had the feeling that he could push at least a little bit more than me, he was a little bit faster. When I was in front I could follow him, but he preferred to be behind," Espargaro said.

"I was pushing until we caught Dovi and then I said I had a chance to beat them, so I waited two laps, rested a little bit behind Dovi, and it took me quite a few laps to overtake him because his bike was so powerful. After I overtook him, I knew that with one lap remaining Aleix would not be able to overtake Dovi so I was finally happy with it.

"I think Dovi had some tyre problems. I think it was the front and not the rear because he had some problems on brakes and was not as strong as at the beginning of the race. On brakes, I could recover the time he put on me on the straights, so it was hard to overtake him. He was not as confident on the brakes and I overtook him at corner four and it was not easy, so I knew that my brother would not overtake him in two laps.

"Every time we are within 16 and 18 seconds [of the winner] and all the races we have finished we are in this gap. It means that we have done a good race because more than 18 seconds is normal and more than 23 is bad. We managed to arrive at 18 seconds, so we did a good job," he added.

"The problem was the first five or six laps because I was really weak with the front. We had problems at the beginning of the race as always: braking fuel tank and traction."