Honda rider Jorge Lorenzo says a "very stupid" training accident left him with a fractured scaphoid ahead of the 2019 MotoGP season.
After injuring his wrist in a dirt bike crash on Saturday, Lorenzo underwent surgery two days later.
Lorenzo will now be forced to skip the first MotoGP pre-season test at Sepang.
"[It] was my first day riding the bike, riding the dirt track in some Italian track," Lorenzo said at the factory Honda 2019 season launch in Madrid.
"One mistake I did was to not properly check the track. In some zones of the track it was some bad mud - big mud - that was difficult to see.
"The surface [looked] perfect and dry, but instead it was this mud.
"When I entered this zone, the front [tyre] closed, and I have a very stupid crash.
"Unfortunately my wrist was not completely healed from the Thailand crash [last year], so I didn't have the perfect mobility, and for sure this affected the pressure with the scaphoid a little bit, and the scaphoid was broken."
Injuries late in 2018 meant Lorenzo was not fully fit when he debuted on the Honda MotoGP bike in post-season testing Valencia and Jerez.
This latest setback has now affected his preparations for his first campaign with Honda.
"Obviously the perfect solution would be to be able to ride and test in Sepang," said Lorenzo.
"But understanding the situation and the lack of days from here to Sepang, we decided I will wait 34 days for the Qatar test.
"I don't think I will be 100%, probably will be [at] 80-85%, to [then] be 90-95% in Qatar.
"Obviously I didn't expect to crash, it was a big pity because it was a very unlucky crash and situation, but now we have this situation.
"We have to work as good as possible with the physios, the machines, with all the process of recuperation, and we have our plan.
"I think on Friday I will start to move the wrist a little bit and little-by-little we will recover [from] the injury."
Lorenzo's injury has created a complicated situation for Honda, as team-mate Marc Marquez is still recovering from surgery performed on his shoulder in December.
Stefan Bradl, who is currently testing the Honda RC213V at Jerez alongside the World Superbike field, will step in for Lorenzo in Sepang.
"It's not the best situation but it's much better that we are like this now than in the middle of the season," said team boss Alberto Puig.
"So we will take it like it is now and our priority is that the riders are fit on March 10, when we start the championship."