During the final seconds of FP2, Fernando Alonso's McLaren-Honda came to a complete stop at the Marina Bay Street Circuit after he reported a gearbox issue.
The Spaniard, though, will be able to replace his gearbox without receiving a penalty as it will occur before the start of FP3.
Finishing the session ninth fastest, the double World Champion played concerns over his gearbox problems.
"We had a gearbox problem but we need to open it to see exactly what happened," Alonso said.
"I think something is broken inside, but that won’t affect the rest of the weekend, because that was just the Friday gearbox and we can put the one from Monza back for tomorrow and get on with it."
Along with Nico Hulkenberg and Lewis Hamilton, the former Ferrari driver also tested out the Halo, saying that he has concerns over entering and exiting the car with the device attached.
"The first impression with the Halo was that it’s quite difficult to get in and out of the car. In terms of visibility it’s obvious it reduces it but I’m sure you get used to it quickly," he explained.
"When the nosecones were raised visibility became a lot worse but two or three years later we were all pretty used to it.
"Once the Halo is imposed there will be an initial impact but we’ll all get used to it quickly. There’s work to be done in terms of design and accessibility has to improve, even for the mechanics to be able to tighten our seat belts."
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