Deletraz will pair up with team returnee Jordan Taylor next season, as WTR with Andretti scales up to two Acura ARX-06 LMDh cars in IMSA's GTP class, after racing alongside Albuquerque and Ricky Taylor at the four IMSA endurance rounds this year.
The Swiss notably qualified on pole at Road Atlanta for the season-ending Petit Le Mans 10-hour race, although WTR missed out on the title following a clash with the championship-winning Action Express Racing Cadillac.
Speaking to Autosport prior to the event, Albuquerque said that Deletraz had justified his selection for a full-time seat based on his performances relative to the team's regular drivers despite comparatively limited mileage.
"I’ve been through that situation as well, I think it’s so hard to prove that you are good," said Albuquerque, who was the third driver for AXR in 2016-17 before going full-time with the squad for 2018.
"Because you do very little testing and they want straight away for you to be on the same pace as the main guys.
"Then you do two races [at Daytona and Sebring] and then you go away and you only show up [again] for Watkins Glen, you drive in the middle or whatever and again - not driving for four months - the team expects you to do as well as the main guys.
"And for the last race of the year, you need to be on the level of the main guys that have been doing all year with the car that you drove three times.
"That’s hard, and he’s been doing well, so [he] totally deserved the seat."
Source: Autosport