News from Jennie Gow, our pit-lane reporter: Mercedes are finally bringing out the hypersoft tyres. They're on Valtteri Bottas' car. Both he and Lewis Hamilton are back in the garage for now. Are we about to see a Mercedes surge? Hamilton second and Bottas sixth, as we stand. Sebastian Vettel still leads. Daniel Ricciardo has climbed to fifth.

Toby Godfrey: Verstappen is undoubtably faster than his team mate but appears to maybe lack the experience, self control atm. A future WC for sure, Hamilton Alonso Senna and Schumacher brilliance, that just needs taming a little.

Jon Harber: Max needs a spell in the Toro Rosso, now only second to Maldonado in crashes : races ratio. Stunned his super licence isn’t littered with points. His ‘entourage’ exhibit the same threatening behaviour. Not a good message for the sport.

Just about at the halfway stage of this practice session, and everyone has now set a time.

Ferrari seem to have a problem. Kimi Raikkonen's car is in the garageand being worked on by the mechanics - as is Sebastian Vettel's. Now we were expecting Ferrari to kick on today after a disappointing Friday. They are first and third in this session, but clearly all is not right with them.

Daniel Ricciardo is now on the hypersofts, so expect him to start moving up from sixth.

Image source, Getty Images

Karin: Funny thing about the headbutting threat reporting. None of the English reports I read mentioned his facial expression. Dutch report said he was grinning, so he was at least half joking.

In fairness, Karin, I've caught the Sky Sports TV coverage and the BBC radio coverage this weekend, and they have both made clear that there was a jokey tone to what he was saying. You may have a point, though, that not everyone has made this clear.

Verstappen is immediately up to third - and quickly down to fourth, as Lewis Hamilton responds by climbing to second. Sebastian Vettel still leads. Hamilton looked good for a leading lap, until he lost position on the final part of the circuit and almost went into the wall.

And bang on cue, Max Verstappen joins us. There was much talk about his "threat" to headbutt anyone who kept mentioning his erratic record this season - but his two firsts in practice yesterday were the perfect response.

We've had 20 minutes of third practice, and we're still waiting for Max Verstappen to set a time. He's keeping us waiting...

Sam Tingey: I personally think everyone needs to stop and think. We cannot question his talent or abilities, just look at how he drove to win his first grand prix. In sport everyone goes through a blip in performance and this is just what he is going through at the moment.

Peter Clews: Verstappen's fast and aggressive and is a reminiscent of Schumacher. He lacks forward thinking though and drives in the moment. Once he develops a more strategic mind he'll easily be winning more and making fewer errors.

Sebastian Vettel, picking up speed, edges ahead of Kimi Raikkonen in 1:12.235. Lewis Hamilton is out on the ultrasofts for Mercedes, and is fifth.

Image source, Getty Images

Yellow flagpublished at 16:16 British Summer Time 9 June 2018

16:16 BST 9 June 2018

Stoffel Vandoorne has come a cropper here at Turn Three. He hit the wall yesterday, and now appears to be stuck sideways on - at least briefly. He tries a multiple-point turn. Jolyon Palmer, commentating for the BBC, suggests it's an 11-point turn. My colleague Matt Warwick suggests it's 15 points. Anyway, Vandoorne eventually gets going again, and the yellow flag period ends.

Now Valtteri Bottas is ready to go for Mercedes - on the ultrasoft. So they're still hanging back on the hypersofts for now.

Sebastian Vettel, who had a bit of a rough time of it yesterday as he was only fifth fastest, is out there too - along with Fernando Alonso, who almost clips the wall of champions on his first lap. He's currently third fastest. with Raikkonen leading the way and Ricciardo second. It's an hour-long session this, and we've just under 50 minutes to go.

Image source, Getty Images

Mercedes hanging back for the moment. Valtteri Bottas doesn't have any wheels on his car yet, while Lewis Hamilton isn't even in the garage yet.

Kimi Raikkonen is straight out in the Ferrari - he's on the hypersoft tyres. Red Bull's Daniel Ricciardo has gone out on the ultrasoft - he wants to do some long-run practice as well as getting some good times in before qualifying.

Image source, Getty Images

Sam Dyson: I think Max just needs two or three good, clean races then he will be fine. If he can get a win this weekend or at least a top 5 position then I think a lot of the hate towards him will go away.

Kristine Kirby: Max Verstappen is turning into #F1's Sergio Ramos with talk of head butting.

As Andrew Benson alluded to a few minutes ago, there was a fair bit of talk about tyres yesterday. Pirelli have seven dry tyres in their range this season - superhard, hard, medium, soft, supersoft, ultrasoft and hypersoft. The softer the tyre, the faster you can go - in theory.

We've got the three softest tyres in the range available this weekend - and it's the use of the hypersofts, which debuted in Monaco, which have caused the intrigue. Mercedes kept all of their hypersofts back - how will they use them today?

Third practice is under way.

DJ: That must’ve been one hell of a groundhog to do that damage by running into a car! You sure it wasn’t a Rhino wearing a fluffy coat?

Image source, Getty Images

Andrew Benson
BBC Sport’s chief F1 writer in Montreal

What does Saturday at the Canadian Grand Prix hold? It’s still sunny and warm, albeit with a few more clouds than on Friday, but conditions are fundamentally the same as Friday, when Max Verstappen topped both practice sessions in the Red Bull, perhaps setting out to prove a point after his difficult start to the season and the controversy he caused with his “head butt” comments on Thursday.

Lewis Hamilton, the master of Montreal, was ‘only’ fourth fastest in his Mercedes, after playing down his chances this weekend to the media on Thursday because of the problems that have led Mercedes to delay their engine upgrade when all the other engine manufacturers have one.

But he’s kidding no-one in the paddock. Hamilton’s fastest time was set on the super-soft tyre, the hardest in Canada this weekend, while all ahead were on the hyper-soft, which is at least a second quicker.

Mercedes, who have fewer sets of hyper-softs than any other team, will try them for the first time in final practice. The suspicion is Hamilton will prove to be in a league of his own. Is that how it will turn out?

Here's today's menu. Third practice is at 16:00 BST - so around 10 minutes away - and qualifying is at 19:00. We'll keep you up to date with the key moments, and if you live in the UK, you can refresh this page around 15:55, click the tab at the top and listen to live radio commentary.