Sebastian Vettel has described Fernando Alonso's accident at Barcelona as "strange" while the Spaniard's manager has denied reports that he was unwell before the incident.
Double World Champion Alonso was forced to spend Sunday evening in hospital after he picked up a concussion during a crash on day four of the second pre-season test at the Circuit de Barcelona-Catalunya.
McLaren initially released a statement saying a CT scan has showed that Alonso "is uninjured and fine", but they later announced that he would remain in hospital overnight.
McLaren Racing Director Eric Boullier said: "Fernando's accident was just one of those things that happens in testing.
"Fortunately, he's fine, but was concussed during the accident, which therefore required an overnight stay in hospital as a precaution. That's normal practice after a concussion."
McLaren, though, haven't released much information about the crash itself and Ferrari driver Vettel, who was behind Alonso on track when the incident took place, is also unsure what happened.
"The speed was slow – maybe 150kph. Then he turned right into the wall. It looked strange," the German said.
Four-time Champion Vettel, though, hopes to see the McLaren driver back in action soon.
"I'd like to wish Fernando a quick recovery," he said. "Luckily, we have already received some good news, so I hope he will be back in top form at next week's test."
Meanwhile, Alonso's manager Luis Garcia Abad has denied reports that the 33-year-old was under the weather before the crash.
"We reject any speculation that he was unwell before the accident. The car locked up, the wind was fierce and he just went into the wall," he told Marca.
"He went to hospital as a precaution, they did all the relevant tests, and the results came back positive. The contact with the wall caused the damage.
"He's in bed, comfortable and relaxed. Everything that has happened is pretty normal in these circumstances. He is going to be under observation for 24 hours, which is protocol."