Ferrari designer Simone Resta will take up a "very senior position" at Haas.
In 2018, Resta was loaned to Ferrari-powered Alfa Romeo, another team that uses customer Ferrari engines and runs Ferrari junior driver Antonio Giovinazzi.
Resta returned to Ferrari last year, but now - hot on the heels of Ferrari placing Mick Schumacher at Haas - the 50-year-old Italian engineer is now moving to the small American team.
"We are still defining his position," Haas boss Gunther Steiner said in Bahrain, "but for sure it will be a very senior position, obviously."
He denied that Resta's move is directly linked with the arrival of high-profile Ferrari junior Schumacher.
"The connection to Mick is not direct," Steiner insisted.
"Obviously we work very close together with Ferrari, so when it was discussed that we needed to reinforce our technical team after we went a little bit backwards the last year with the pandemic, he was a good choice.
"But it has nothing to do directly with Mick driving for us."