(CNN) -- They are two of the biggest names in motorcycle racing, and tensions were high the last time they were on the same team, but Jorge Lorenzo says rival Valentino Rossi's return to Yamaha is "good news."
Rossi left the Japanese team in 2010 after Lorenzo won his first world MotoGP championship, ending the Italian's two seasons of dominance.
Rossi, who won the world title four times with Yamaha and three with Honda, has struggled to be competitive since joining Ducati, managing just two podium placings in 28 races.
The 33-year-old has agreed a deal for the 2013 and 2014 seasons, resuming a partnership which Yamaha described as a "super team" when the news was announced last Friday.
"I think our relationship has got better, though maybe it's got better because we were in different teams," Lorenzo said on the MotoGP website ahead of this weekend's Indianapolis Grand Prix.
"It's good news for Yamaha because we achieved a lot of good results together. It's a big motivation to have him back because I always like to have the best riders in my garage.
"Valentino is one of them. I assume trying to beat me will be a big motivation for him. For Yamaha, it will be a good thing, that's the most important thing."
Rossi won 46 races in his seven years at Yamaha, but his final season was blighted by injuries and Lorenzo took full advantage.
The Spaniard lost his crown to Casey Stoner last year but tops this season's standings by 23 points from Honda's Dani Pedrosa with five wins and four second-placings from 10 of the 18 races so far.
Rossi is eighth overall, but still ahead of Lorenzo's 10th-placed American teammate Ben Spies, who will leave Yamaha at the end of this season.
"Someone who has talent normally keeps it and doesn't lose it like this in two years," Lorenzo said of Rossi.
"He is still young enough. He is 33, he has won a lot of races. With the Yamaha a better bike this year, it will be easier for him.
"It's true that us younger riders are getting stronger, more experienced and more consistent, but we have to remember that Valentino has won a lot of races. We have to respect that and keep it in mind."
The 25-year-old missed out on a podium place at Indianapolis last year when Spies passed him to take third, but won the U.S. race in 2009 and has twice been third himself.
"I really enjoy riding the Indy track, and have good memories here from my podiums in 2008 and 2010 and my great win in 2009," Lorenzo said.
"Last year I really struggled with grip in the race so I hope we can improve that this year. I've had a nice break but also been training to make sure I'm fit for this weekend!"
Honda's Stoner and Pedrosa have won the last two Indianapolis races, and both are seeking to cut Lorenzo's lead following MotoGP's midseason break.
"In these two weeks I was able to relax a little, enjoy time with friends and get back into my training," Pedrosa said.
"At this time of year, Indianapolis is normally very hot so fitness is always key. I enjoy riding at this track and I've had good results in the past. I am really looking forward to this race and will fight to win and maintain the consistency we have showed in the first part of the championship."
Stoner is 32 points adrift of Lorenzo in third place despite winning four races this season, which will be his last as he plans to retire after the final race in Valencia at the relatively young age of 27.
"I'm not the biggest fan of Indy, mainly because we don't go on the historical track but the infield and in the wrong direction," said Australia's two-time world champion.
"The track is very flat and plain, also very tight. There are a couple of corners that can be fun but the majority are difficult, tight and there isn't any natural flow to the track."