The Formula One circus heads to its traditional European heartland for the first time this season as Barcelona’s Circuit de Catalunya plays host to the Spanish Grand Prix.Defending champion Lewis Hamilton holds a four-point lead over his rival Sebastian Vettel by virtue of his win last time out in Azerbaijan.Here, Press Association Sport takes a look at the key talking points ahead of the fifth round of the championship.

1. Fuel leak disrupts Hamilton’s preparations

Hamilton’s departure from New York – where he spent last weekend attending the Met Gala – was delayed on Tuesday evening by a British Airways fuel leak.

Hamilton, who posted the update to his Instagram account, will hope it is the only mechanical problem he faces this week as he bids to follow up his opening victory of the season with another full quota of points in Barcelona on Sunday.

Hamilton was fortunate to win at the last round in Azerbaijan, given that he was off the pace all weekend, but the Brit will hope that Barcelona’s Circuit de Catalunya – a track where Mercedes held the upper hand over Ferrari during pre-season testing and a venue where he overtook Vettel to win last year – will be kind to him once more. A commanding weekend for Vettel, however, may suggest to Hamilton that his chances of a fifth crown could be beyond him.

2. Welcome to Miami?

We will get a clearer indication as to whether Formula One will head to Miami next year when its City Commission vote on the sport’s 10-season proposal on Thursday.

F1 recently announced plans to hold a street race in downtown Miami next October, and it is understood that its American owner Liberty Media is confident the project will be approved. The proposed track includes the port, runs along Biscayne Boulevard and loops around the American Airlines Arena.

The layout, however, got a thumbs down from the sport’s defending champion after Hamilton wrote on Instagram: “OK, so I’ve just seen the design of the Miami track. Nah bruh, it’s not the one. Let me design it.”

3. Red Bull in the spotlight

All eyes will be on Max Verstappen and Daniel Ricciardo this weekend following their collision in Baku.

For Verstappen, the coming together marked his third high-profile incident in as many races, and he is already 52 points behind Hamilton in the championship race.

The 20-year-old Dutchman’s gung-ho style has won him plenty of suitors in recent years, but he is in desperate need of an error-free weekend to prove this run of form is just a blip.

As for his team, Christian Horner revealed after the Azerbaijan race that Red Bull will review their rules of engagement. It is likely that Ricciardo and Verstappen will be allowed to continue to race, but a repeat of their crash in Azerbaijan is almost unthinkable.

4. McLaren hoping to turn corner

The opening leg of the European season is synonymous with the start of the development war as the teams head to Barcelona armed with a series of updates, and McLaren will be among those hoping for a change in fortunes.

Fernando Alonso is a miraculous sixth in the standings after using all of his race craft to secure 28 points from the opening four rubbers, but his car, particularly in qualifying, has been desperately slow.

Alonso won on his World Endurance Championship debut with Toyota at Spa-Francorchamps last weekend, but returns to his day job expressing more than a hint of caution. He said: “I know we have some developments in the pipeline, but we also know there is no magic bullet that will propel us to the front of the grid overnight.”

5. Bottas receives famous trophy

Valtteri Bottas was awarded the prestigious Bandini Trophy in Brisighella, Italy on Saturday in recognition of his breakthrough performance last season which saw him secure his first wins and pole positions, helped, of course, by his move from Williams to Mercedes.

The Finn has out-performed team-mate Hamilton at two of the four races this year, and probably should have won in China and Azerbaijan, too, only for his triumphs to be derailed by a safety car and puncture respectively. Bottas is out of contract at the end of the year, but could yet be retained if he keeps Hamilton firmly on his toes.