Valentino Rossi says there's still "a long way" for him to go before he matches Yamaha MotoGP teammate Maverick Vinales, after finishing second to the Spaniard in Argentina.
After recovering from a difficult pre-season to finish third in Qatar, Rossi's upward trend continued at Termas de Rio Hondo, as he came out on top against Cal Crutchlow to secure second place.
The Italian finished 2.915s behind a dominant Vinales, who was never threatened when he inherited the lead of the race on the fourth lap as a result of Marc Marquez's crash.
While satisfied to complete a Yamaha one-two, Rossi admitted the gap between himself and Vinales means he still has a lot of work ahead to get on level terms with his new teammate.
"Sincerely when I crossed the [finish] line I thought [the gap to Vinales] was less than 2.9 seconds, but it was," said Rossi. "[There's a] long way to go still.
"The race was good, because I could push to the end, I felt comfortable with the bike. I felt better with my physical condition, in Qatar I arrived [at the finish] more tired.
"Here I could push, and also the fight with Cal was great. He was very fast, but when I followed I saw I had a bit more. But I don't think if I overtook him before I could catch Maverick.
"It was an important second place, because Yamaha is one-two, and also for the points in the championship."
Rossi finds himself second in the points after two races, having scored 36 to Vinales' 50.
Despite suffering a "disaster" of a pre-season, he said his Qatar showing had given him confidence that he could rebound from a poor practice showing and still perform in the race.
"The pre-season for me was a disaster, I was very sad," said the 38-year-old. "But the important is just Sunday afternoon, when you cross the line.
"In my long career I learn you always have to be concentrated, never give up, that a lot of things can happen.
"The race in Qatar gave me a good feeling, a good vibe, because I started to know better the bike and I know also if I suffer I can be competitive on Sunday.
"It's a good result, also because I have more points than [this time] last year."