Mazda Motorsports director John Doonan says its 2018 IMSA WeatherTech SportsCar Championship driver lineup will be decided by the end of this season, with the intention of continuing with its “homegrown” talent pool despite the introduction of Joest Racing to the equation.

The legendary German squad will take over as the factory team running the pair of Mazda RT24-Ps, beginning with January’s Rolex 24 at Daytona, with the current SpeedSource-run program coming to an end, effective immediately.

While all four of Mazda’s current full-time Prototype drivers: Jonathan Bomarito, Tristan Nunez, Joel Miller and Tom Long, will be part of Joest’s testing and development program, which is set to get underway next month, its 2018 driver lineup has not yet been determined.

However, the addition of Joest will not result in a change of Mazda’s philosophy of promoting from within, according to Doonan.

“We’re really proud of the driver development program,” Doonan told Sportscar365. “We have a huge amount of confidence in the group we have in the prototypes. I’ve told them time and time again that I would put them toe to toe with anyone in the sport.

“We are going to start testing with the current lineup in the next 30-45 days. You’ve seen guys like Spencer Pigot, Marino Franchitti, Ben Devlin and James Hinchcliffe, all guys who have been a part of our family, make appearances in the long races as well.

“We have to get out and test. We have to use our system and Joest’s experience to bring the absolute best to the table when it comes time for the Rolex 24 at Daytona to kickoff.”

Doonan expects an announcement to be made prior to October’s season-ending Petit Le Mans, in order to give its current drivers as much time as possible to secure other rides, should a change occur.

“We’ll make an announcement before the end of the season,” Doonan said.

“Ralf [Juttner] and Mr. Joest have not brought me a list of names. They recognize and respect and appreciate what we have done.

“Also, one of the reasons to bring them on as a partner is to leverage their experience. Engineers, chemistry between engineers and drivers, is critically important so we’re going to use those things to bring the best foot forward.”

With testing set to begin shortly in Europe, Joest Racing Managing Director Ralf Juttner said he’s looking forward to getting to work with Mazda’s current crop of drivers.

Nunez, Miller and Long have all been part of the Japanese manufacturer’s Prototype program since its formation in 2014, with Bomarito joining the trio one year later.

“We have not worked with any of these drivers up to now,” Juttner said. “I’m looking forward to do that finally. Of course, I watched carefully a lot of the last races, and tried to figure out.

“I’m very open to start working with those guys, and that will happen, as we said, very soon, 30, 40 days. Yeah, the rest we will see. As John said, he hopes to have a final driver lineup by the end of the season. Whether there is a change or not, we can’t tell yet.

“It’s not that we are coming with a whole wagon of drivers in our bag trying to bring those in. That’s not the case. We respect that it’s Mazda’s responsibility to contract the drivers.

“We will discuss together, as we have done in the past, because it is important, because the driver and the team relationship is a very important one. But I’m sure that we will find a good solution there.”