On the eve of the Red Bull U.S. Grand Prix at Laguna Seca at Thursday's press conference, Spies, joined by championship leader Jorge Lorenzo, Casey Stoner, Valentino Rossi and Colin Edwards, confirmed that he will be leaving the team at the end of the year.
This has subsequently sent so-called "silly season" into overdrive with regards to riders' contracts, especially with Ducati Team's Rossi considering his future options for next year.
Spies, speaking ahead of the first race in the stateside double header, had leaked snippets of information earlier in the week about his plans to leave the Japanese racing outfit.
He said: "I've known for quite a bit what my personal decision was and I thought this was the right time to do it with all the contracts happening with other riders. There's a litany of reasons behind it - just getting back to stress-free and doing what I want to do and finish out the season strong. That's all that's going to be said about it at this point until I'm ready to talk about the future. It's not going to change anything. For sure, especially at Laguna we're going to give 100 per cent and we want to do what we're capable of doing and what the bike's capable of doing for the team.
"Nothing changes from that standpoint. I just made a decision, and wanted to get it off my chest and out of the way. Now that we've done that now I feel like the weight of the world is off my shoulders and I can do what I set out to do."
Since the American's earlier announcements, Rossi, a previous Yamaha rider, has had the rumour mill turning at ever-greater speed, as speculation over his future in 2013 mounts. He commented: "The situation is quite clear. I still haven't decided, as it is a bit to early. I have spoken a lot with Ducati about next year, but still waiting for some important ties and some important things on the contract.
"And I also have some other options for next year. But I think the situation will be clearer in the next weeks, and I think in the summer break I will decide about next year."
Following a test after the last race that was stopped short with technical issues, he is not racing with as many upgrades this weekend as previously hoped: "More or less we have the same bike from Mugello, and we have to wait a bit more for something different. This track is very tough; it's something different compared to most of the other tracks. It's more old style up-and-down, very tricky, but I like it.
"For this year we need to improve at the beginning [of the race] where I'm not able to go fast enough with the top guys. So we have some ideas for the settings this weekend to try and improve that."
Spies' teammate Jorge Lorenzo, who comes to the U.S. in strong form after a dominant win in Mugello two weeks ago, is confident ahead of the race: "Fortunately for us in the last race in Mugello we got the victory and now we have quite a big advantage. It's only 19 points, but it's better to have it than not to have it. And now we come to a track that I have been quite fast at in the past, and it's always special to race here in America.
"It's a track where I have crashed many times in qualifying, and also in the race in 2008. But I feel really good at this flowing track. It's also really short, so the race will be really tough physically, probably as tough as Sachsenring. But we are ready, we're in good shape and the bike is working really well this year."
Repsol Honda Team's Casey Stoner, who won at the track last year with a spectacular ride, struggled with his bike in the last race, yet will be using a new engine to help improve this weekend: "The last two races haven't been good for us with a couple of big mistakes from me. Things haven't gone so well. We tested a new engine [after Mugello], which was very positive. It gave us a lot more smooth power and some small advantages in some areas so we're quite happy with that.
"Chassis wise I didn't feel anything better than what we've got now, so we're not going to be using that here. It's [Laguna] a very particular track and I think if there were a couple of spots with a bit more speed then there wouldn't be many tracks better than this. It's so technical and there are some areas that really catch you out - blind corners, blind braking points - it's a really enjoyable track."
NGM Mobile Forward Racing's Colin Edwards, who has been struggling this season on his team's Suter-BMW CRT project, and recently tested and FTR-Honda and a BQR-FTR machine, stated there might be some changes happening after this race. He said: "It's [the season] been tough you know. I've heard rumours we're going to get on Aprilia [ART] at Indianapolis.
"It's not going to compete with these guys [factory riders], but it's at least the best CRT bike out there at the moment. But if that happens it's a step forward."
Many riders had kept themselves busy in the U.S. earlier in the week, with some taking part in some rather unusual activities. LCR Honda MotoGP's Stefan Bradl wheelied his RC213V across San Francisco's Treasure Island, before winding his way down the iconic Lombard Street and taking part in a lecture at Stanford University labelled "Embracing Risk in the Pursuit of Victory". Ducati Team's Nicky Hayden took the opportunity to step into Sony Pictures film studio in Los Angles and check out how non-racing entertainment is produced, and get a first hand glance at some rather special props.
Last but not least the Yamaha Factory Racing duo of Lorenzo and Spies were joined by Monster Yamaha Tech 3 riders Cal Crutchlow and Andrea Dovizioso as Yamaha USA filmed their yearly spoof promo video at the company's headquarters in LA. Lorenzo, who two years ago was a janitor, was promoted to "Honorary CEO".