DISCLAIMER: All of the information is compiled from reputable sources, however, all possible scenarios must be considered speculation unless confirmed by any team, driver, or manufacturer discussed therein.

Racing fans call it Silly Season. Baseball types call it the Hot Stove. Either way, with the 2017 Autobacs Super GT Series completed, and preparations beginning for the 2018 season, there is a constant thread that applies to all form of motorsport – that change is inevitable, and that change will happen over the next few months.

The GT500 category is already one of the most competitive classes of racing on earth, and with an influx of potential free agents from outside the series, as well as young stars of the future ready to take their place in the top level of Super GT, the 2017-18 Stove League promises to be one of intrigue.

With the help of the most recent issue of auto sport Magazine of Japan (volume 1470, released on Friday), Super GT World runs down the potential scenarios for Lexus, Honda, and Nissan in the 2018 season to come.

The GT500 grid will remain at 15 cars – 6 Lexus LC500s, 5 Honda NSX-GTs, and 4 Nissan GT-R GT500s. But within the three manufacturers’ rosters, there is expected to be quite a bit of change for 2018.

At Lexus, two prominent names linked to the company are in the frame for a full-time GT500 drive. Kamui Kobayashi and Kenta Yamashita each made one-off appearances in GT500 for Lexus Team WedsSport Bandoh in 2017.

Kobayashi, like his fellow Toyota factory ace Kazuki Nakajima, could potentially be a very busy man as it is possible for him to run Super GT, Super Formula, and the 2018 portion of the WEC season to come – with just one clash of dates, the Fuji 500km with the 6h of Spa-Francorchamps on the same week.

Yamashita, the former All-Japan F3 champion, stepped up to Super Formula quite impressively in 2017, and enjoyed his best-ever GT300 campaign with VivaC Team Tsuchiya as well. The 22-year-old Toyota Young Driver Programme (TDP) prodigy is ready to make the jump to the premier class of Super GT.

With the incredible talents of both Kobayashi and Yamashita coming in, Lexus are now in a spot where they may have to cast off some very talented and accomplished GT500 drivers in order to make room.

The first name at risk of being pushed out is Andrea Caldarelli, who has finished 2nd or 3rd in the championship three of the last four years. The writing may have been on the wall for this potential departure however, with the Italian signing a factory racing contract with Lamborghini in 2017. The Lexus LC500 is faster than anything in the GT3 landscape, but the allure of being an Italian driver with an Italian manufacturer is pretty irresistible in its own right.

The second, as speculated by auto sport and even through cryptic social media postings in the last two weeks, is Kohei Hirate, who is just a year removed from winning the GT500 championship with Lexus Team SARD. Hirate updating his CV from a coffee shop isn’t a guarantee of a drastic change of plans in the future of the 2-time GT500 champion, who was still incredibly competitive in several late race battles, and is still just 31 years old.

An unnamed international driver may also be in contention – one name that has popped up is Formula 1 free agent, Pascal Wehrlein, who does have experience in similar cars as a former DTM champion and race winner, and would be a high-impact acquisition. José María López, a triple World Touring Car Champion, has told press in his native Argentina that he’s looking towards Super GT as a post-WEC option for 2018.

The rest of the Lexus roster seems secure, including Yuji Tachikawa, the elder statesman of the crew who seems set to return to Lexus Team ZENT Cerumo for his 20th season.

It also includes Ryo Hirakawa, and as speculated by the staff at auto sport, there is a possibility that if the 2017 GT500 Drivers’ Champion can continue his success in Japan – specifically, if he can secure a return to Super Formula and win the championship, that he could qualify for an FIA Super License and race in Formula 1. Whether it’s in F1 or at Le Mans with Toyota, Hirakawa’s talents have long beckoned for the world’s stage.

Toyota is likely to continue its support of LM Corsa and their two Lexus RC F GT3s, and apr Racing and their two Toyota Prius GTs. Watch for TDP prospect Ritomo Miyata, the two-time F4 champion, to be in the frame for a Super GT debut as a GTA scholarship winner.

For Honda, who enjoyed a resurgent 2017 season, one name and one name alone holds the key to the off-season.

Jenson Button, 2009 Formula 1 World Champion, was a sensation in his one-off Super GT debut at the Suzuka 1000km. Button has a goal to return to full-time racing in 2018, and Super GT is his main priority. For a time, it looked as if he might defect to Nissan due to his ties with the McLaren F1 Team, who are switching from Honda to Renault power in 2018.

But now that Button is no longer with McLaren after the 2017 season, he is all but certain to join Honda in a full-time capacity in 2018, continuing a relationship that spanned over half of his F1 17+ year career with Honda power.

But as reported by auto sport just after the Motegi GT Grand Final, Honda motorsports president Masashi Yamamoto has other international drivers in the apart from Button – and it’s likely that a second non-Japanese driver could join the GT500 roster.

And the rumour is that it is a young driver who is set to take part in the upcoming Super Formula rookie test at Suzuka Circuit. Two names on the entry list for that test, who will test Honda-powered cars, immediately jump off the page: Ex-F1 trailblazer and Formula 2 race winner Rio Haryanto of Indonesia, and multi-level single seater race winner Álex Palou of Spain. While Narain Karthikeyan isn’t as young as the other two, he does have an “imminent” Super GT test coming up, likely with Honda.

That said, the state of flux of Honda’s Formula 1 involvement also means that their three European-bound prospects of the Honda Formula Dream Project (HFDP) could also be on the move. Of the three, it’s most likely that it’ll be Nobuharu Matsushita “coming home” to race in Japan after three years in Formula 2, and with no clear path to F1 in sight, a move to GT500 seems likely for the 24-year-old former F2 race winner. Nirei Fukuzumi and Tadasuke Makino are set to continue their European challenges.

As it pertains to the new-to-Japan Honda NSX GT3, there are no plans for Autobacs Racing Team Aguri (ARTA) to take on the car – as has been expected since the minute the NSX GT3 first broke cover.

CarGuy Racing are the first customer, and up to three teams may join them on the GT300 grid with NSX GT3s of their own: Ryo Michigami‘s Drago Corse team, current Mother Chassis runners Team Upgarage, and a team run by Yuji Ide. Any one of these teams could be a landing point for a young Honda-backed driver like Palou, Hiroki Otsu, or Keishi Ishikawa, or a displaced GT500 driver from the current roster – of which Kosuke Matsuura might be most likely to step aside.

The five GT500 teams will remain the same for Honda, it appears, despite the off-season rumours of a return for Dome Racing to the premier class.

Nissan are highly unlikely to expand and add a fifth GT500 team this year, but as reported by auto sport, the identity of one of their four premier class teams could change – and as soon as this coming season.

MOLA International, winners of back-to-back GT500 titles in their first two seasons in 2011 and 2012, may vacate their GT500 entry this off-season, and would in turn, be replaced by the B-Max Racing Team.

B-Max stepped up to Super Formula in 2017 after years of success in Formula 3, and they’ve been the title sponsor for NDDP Racing for several years. They’ve built a successful foundation in Japanese motorsport in a fairly short time.

Mitsunori Takaboshi is likely to move up to GT500 full-time – and no driver has looked readier for the opportunity than the newly-crowned All-Japan Formula 3 champion, who’s won races in GT500, raced in Europe, and even had a stellar one-off GT500 outing with MOLA in 2016, finishing third in the Suzuka 1000km. For 2017, he’s been mentored by the man, the legend, that he appears set to replace, Satoshi Motoyama.

After 22 seasons, 21 in GT500, Motoyama turns 47 before the start of next season, and he and Tachikawa from Lexus are the last of their generation left racing. It’s rare these days for a Super GT driver to get a NASCAR-style retirement tour in their last season, but if anyone’s deserved it, it’s Motoyama – a three-time GT500 champion and four-time Japanese Top Formula champion, a first-ballot Hall of Fame driver in any regard.

There’s also a very vague rumour in the new auto sport that just states that Katsumasa Chiyo is a driver to watch in the off-season. The former Blancpain GT Endurance champion, and former Bathurst 12 Hour winner, is still searching for his first GT500 race win – what’s next for the popular NDDP graduate?

Also, the second-generation Nissan GT-R GT3 has no identified customers as of yet. NDDP Racing would likely be the first in line for the revamped GT-R GT3, but depending on what happens with title sponsor B-Max Racing, they may need a new sponsor – and with Takaboshi’s graduation, they may also need a new young driver to build around. Kiyoto Fujinami has prior ties to Nissan, and Shinji Sawada is a talented B-Max sponsored driver who could also be next in line.

Everything else appears stable.