Callum Ilott has been designated as Alfa Romeo's F1 reserve driver in Miami, the IndyCar racer substituting for Robert Kubica who is competing in the WEC round at Spa this weekend.
Ilott, a former member of the Ferrari Driver Academy, officiated as Alfa's reserve last season alongside Kubica, and took part in two FP1 session in Portugal and in Austria.
This year, the 23-year-old Briton is competing full-time in the NTT IndyCar Series with Juncos Hollinger Racing.
"Callum is part of the team and he was with us last year," Alfa team boss Fred Vasseur told Motorsport.com.
"He knows perfectly the team. The car not, for sure, but he knows the team. And we are all close to him. He did a good job with us in the past."
Although Ilott's presence this weekend in Miami is a one-off, he could be called back again by the Swiss outfit in the future depending on his availability relative to his IndyCar schedule.
"He's here race-by-race. He has his own commitments, and I don't want to disturb him. But the fact that he was here in the U.S. it also made sense for him," added Vasseur.
"We'll see in the future, but if sometimes Robert is not available, it absolutely makes sense to go with Callum. We don’t need to have a contract – he’s part of the family."
Callum said that he was more than happy to put himself on stand-by for Alfa in Miami, especially as he had planned to drop in on his F1 colleagues this weekend.
"I wanted to come down here anyway," he said. "They called me two weeks ago, so it worked out quite well to be able to help out and be here.
"The last time I drove this car in the sim was probably in the early stages of development. A lot of the systems are very similar to previous years, but obviously the fundamentals are very different.
"It's just nice to be back and see some people I haven't seen for many months. I was in this environment for a while, in F3 or F2, and I know a lot of people here.
"So to come back and enjoy some good times with people and be able to kind of be properly involved is great. It's a bit very refreshing."