MotoGP's reduction in collective full-grid testing in recent years has accentuated the role of the test rider - a role filled at every MotoGP factory, sometimes by multiple riders, virtually all of them having some form of previous premier-class race experience.
They are crucial figures for development, given the teams' regular race riders struggle to fit in comprehensive test work in race weekends, especially under the demanding sprint format.
But while most of that work takes place in private running, away from the prying eyes of media and television audiences, testers are also often seen as injury stand-ins or wildcard entries. In both cases, these appearances are almost always used as an opportunity to cram in more development work.
Here's the rundown of who each of MotoGP's current five factories use in primarily testing roles.
Ducati
Ducati's spectacular MotoGP development, in which long-serving tester Michele Pirro has played a huge part, has ironically led to Pirro getting fewer premier-class race opportunities.
Under the revised concession system, Ducati - due to its relentless winning and points-scoring - has been listed as a 'Rank A' manufacturer, which among other restrictions means it is not eligible for any wildcard entries in a season.
So its tester Pirro, who has year after year had a MotoGP start here and there in a wildcard capacity, can only get on the grid now if a Ducati regular is injured.
His primary responsibility - aiding bike development outside of race weekends - is still clearly going very well, though, and Pirro is keeping himself race fit in Italian Superbikes, where he has now won seven titles.
KTM
Veteran Dani Pedrosa may well be the biggest-name test rider in MotoGP history, having moved into that role after concluding a premier-class career that yielded 31 wins.
Pedrosa is widely seen as one of KTM's most valuable assets - and is thought to be slowly but surely transitioning into more of a managerial role, something that's already transpired with his predecessor Mika Kallio.
Pedrosa has been blisteringly competitive in his wildcards with KTM, while KTM's new test rider Pol Espargaro - who is six years younger than Pedrosa - has also been credible and looks on course to succeed Pedrosa as the test team's focal point.
KTM also has Jonas Folger on the books as another test rider, having brought him back into MotoGP after health issues curtailed his promising full-time premier-class career after one season in 2017.
Aprilia
Former World Superbike regular Lorenzo Savadori, whose most notable international achievement may well be finishing second to Johann Zarco in the inaugural Red Bull Rookies Cup, is potentially the least-heralded of MotoGP's test rider ranks.
But Savadori is highly-respected within Aprilia, having played his part in a major step in the RS-GP bike's competitiveness, and continues to rack up starts in both a wildcard capacity and as a stand-in.
In the past, Savadori shared the role with Matteo Baiocco, but while Baiocco remains an integral part of Aprilia's MotoGP programme he is now a rider coach and analyst and has earned rave reviews from Aprilia veteran Aleix Espargaro in that position.
Yamaha
Cal Crutchlow reunited with Yamaha as a test rider at the conclusion of his full-time MotoGP career, replacing Jorge Lorenzo in the process.
But Crutchlow's work at honing the M1 has been severely limited in 2024 due to complications from hand surgery.
Wildcard starts that he was set to make - and the testing work contained within - have gone to World Superbike rider Remy Gardner instead, while fellow MotoGP winner Andrea Dovizioso has also been testing and working with Yamaha in Crutchlow's absence.
And Yamaha is thought to have all but sealed the signing of Augusto Fernandez, currently at Tech3 Gas Gas, as a test rider for next year.
As a 'Rank D' manufacturer, Yamaha is allowed to use its race riders in private testing - and does - but the calendar of races is busy enough to the point where it still has an acute need for a strong tester, or two.
Honda
Like Yamaha, Honda is a 'Rank D' manufacturer and tests extensively with its race riders - but that has not stopped it from bolstering its test rider ranks.
Stefan Bradl has carried out most of the work for many years, but while Bradl has been retained for 2025 he is being joined by Aleix Espargaro in the latter's first gig since calling time on his full-time racing career.
But Honda is also pivoting Takaaki Nakagami, its long-time LCR rider, into a test role for 2025 - in which he will serve as a bridge between its Europe-based racing operations and the development work back in Japan. The connection between the two, Nakagami himself has admitted, has been lacking.
It's a potent test roster - but it will be something of a minor headache, then, to spread just six available wildcard slots among those three.
