Haas and Alfa Romeo won't use the new Ferrari engine in Spain
F1 News
As Ferrari announced on Tuesday, they will introduce their second specification power unit for the Spanish Grand Prix this weekend. However, close relatives Alfa Romeo and Haas will continue to run with the first spec.
According to the well-informed F1 journalist Albert Fabrega, the engine upgrade won't be installed into Ferrari's partner teams. Though there's no explanation for why.
Sorry, Alfa Romeo, not Ferrari!
— Albert Fabrega (@AlbertFabrega) 9 May 2019
Alfa Romeo and Haas might not want to take the risk. The track in Barcelona also lacks long straights so there's less emphasis on power. During the race weekend build-up, they'll likely be a full explanation.