While there’s still two races to go in this year’s season, the talk of the IMSA WeatherTech SportsCar Championship paddock has largely already shifted to 2018, in what’s shaping up to be some of the biggest off-season changes in recent years.

From the arrival of Team Penske and Acura, to a rejuvenated Mazda effort with Joest Racing and a number of LMP1 factory drivers on the market, the so-called “silly season” is already in full swing, with a number of key moves set to be made in the coming weeks.

Musical Chairs in Prototype

The first domino to fall came last month when Penske confirmed Juan Pablo Montoya and reigning Prototype champion Dane Cameron to its first Acura ARX-05 DPi, leaving a full-time seat to fill in the No. 31 Action Express Racing Cadillac DPi-V.R.

Cameron, however, won’t be the only change within the Action Express squad, with Christian Fittipaldi reportedly set to move to an endurance-only role and Filipe Albuquerque, its current Tequila Patron North American Endurance Cup driver, poised to take over full-time driving duties of the No. 5 car alongside Joao Barbosa.

Ex-Formula One driver Felipe Nasr, meanwhile, is expected to be confirmed as Cameron’s replacement in the No. 31 entry with Eric Curran.

One of the two remaining season-long seats to be filled at Penske, meanwhile, is set to throw off another set of dominos, with Ricky Taylor poised to make the move from his family’s Cadillac operation to the new Acura effort.

Taylor will likely be joined by Helio Castroneves, whose tug-of-war with IndyCar appears to have now gone in favor of a full-season IMSA program, with the Brazilian having tested the Acura DPi earlier this week at Sebring.

Ricky Taylor’s pending departure from the champions-elect Wayne Taylor Racing squad leaves another seat to be filled, with names such as Brendon Hartley having been mentioned, although no firm candidate appearing to be in place.

Hartley, the current FIA World Endurance Championship leader, is understood to be also pursing options in both IndyCar and Formula E, with a deal with Chip Ganassi Racing the likely outcome.

Alex Lynn, who teamed with Ricky and Jordan Taylor for victory at Sebring, meanwhile, is not an option for a full-time replacement due to the Englishman’s new Formula E gig with DS Virgin Racing, with at least two rounds, including Sebring, set to clash with the WeatherTech Championship.

Mazda is the other big question in the Prototype class, with Joest’s involvement likely to bring in at least one new face to the driver lineup.

The team tested ex-Audi LMP1 driver Rene Rast earlier this week at Hockenheim, although the German is unlikely to commit to a full season campaign due to his DTM commitments, where he currently sits third in the title race.

Both Tristan Nunez and Jonathan Bomarito, who also were part of the shakedown, are expected to continue, although the status of Joel Miller and Tom Long remains up in the air.

As of the publishing of this article, only Tequila Patron ESM and the newly announced CORE autosport Oreca 07 Gibson entry have fully confirmed lineups, with both teams remaining with its 2017 drivers.

And with a possibility of more than 15 prototypes on the grid next year, that leaves a lot still to-be-decided.

Changes Likely in GTLM

While BMW, Corvette, Ford and Porsche are all set to return, there will likely be some shakeups in at least two of the driver lineups.

Porsche, which faces a surplus of factory drivers amid the end of its LMP1 program, is likely to see the biggest change, with both Gianmaria Bruni and Laurens Vanthoor expected to move to its WEC GTE-Pro effort.

That is likely to open the door for LMP1 refugees Nick Tandy and Earl Bamber to return Stateside for a full-season campaign. Both will rejoin the CORE autosport-run team for next month’s Motul Petit Le Mans, as a potential hint towards 2018.

BMW will also likely have a revised driver lineup with its new M8 GTE cars, with Martin Tomczyk rumored to move to the new MTEK-run WEC effort.

It would leave a seat open for former GTLM champion Kuno Wittmer, who has been BMW’s endurance driver for the last two years and chomping on the bit for a full-time drive with the German manufacturer.

While all Ford drivers’ contracts, both in IMSA and WEC, are up at the end of the year, no major changes are expected within the lineups, with the same to likely be said at Corvette Racing.

WeatherTech to Scuderia Corsa?

The GT Daytona class could see as many changes as in Prototype, although most deals are still in a very fluid state.

What appears to have already been firmed up, however, is WeatherTech Racing’s move to Scuderia Corsa for 2018, which would effectively take the seats of current championship leaders Christina Nielsen and Alessandro Balzan.

It’s believed Cooper MacNeil, and likely Gunnar Jeannette, will pilot the team’s Ferrari 488 GT3, in what will remain as a single-car operation for the California-based squad.

That essentially puts the defending GTD champions, who are on the brink of locking up back-to-back titles, on the market, in what could trigger a whole new set of dominos.