Dani Pedrosa has withdrawn from the Sepang test a day early due to pain from a knee injury.
The Honda rider underwent surgery in December, having hurt his left knee in a crash at Phillip Island last autumn, and was struggling to complete long runs during this week's test.
With the team planning to focus on race simulations during the final day of testing on Saturday, Pedrosa decided it made sense for him to head back to Spain.
"Tomorrow a race simulation was scheduled but at the end we decided to end the test session because today I could only do five, six laps in a row and tomorrow I won't be able to cover the race distance," he said.
"Last December, in fact, I underwent an intervention to the left knee for the consequences suffered when I slid off in Phillip Island during the last race in October. I only need some rest."
Despite his knee problem, Pedrosa was pleased with the work Honda had managed during the first two days of testing. His new teammate Andrea Dovizioso will stay on for Saturday.
"Today I was much more comfortable on the bike, I could be faster from the first laps and we could work on the bike testing all the items we had to test for this session," said Pedrosa.
"In fact I know this bike, which is an evolution of last year's bike, and this gives me an advantage compared to last year, when the bike was completely new for me. We have pointed out the aspects we want to improve for Qatar."
All of the 2009 season's title favourites have been hampered by physical problems during the Sepang test, with Pedrosa's main rivals Casey Stoner and Valentino Rossi struggling with residual pain from winter wrist surgery and cuts sustained in a domestic accident respectively.