Chief designer Rob Marshall stressed the new chassis is a routine introduction rather than a reaction to Vettel's current form.
The four-time world champion's return of one podium and 33 points represents his worst start to a Grand Prix season since joining Red Bull. He finished behind new team mate Daniel Ricciardo in both China and Malaysia, and was also outpaced by the Australian in the Melbourne season opener.
"Sebastian will get a new chassis for Barcelona, which was scheduled at the start of the season," Marshall said.
"It shouldn't be [beneficial], as the idea is that they are all the same. Drivers don't always want to change them - they can get attached to a particular chassis and when they are on a good run they like to hang on to it for as long as possible.
"From our point of view we'd rather give them one or two new chassis during the season that we have been able to check out in the factory using various testing methods. The next one will be for Dan at some time around Silverstone."
Marshall added the team will be bringing a comprehensive update package to Barcelona, as they bid to overhaul Mercedes' current advantage and prevent a fifth straight win for the Silver Arrows.
"There are a couple of races that stand out as being obvious ones for a major upgrade - that's the first and last European race[s]," he explained.
"The Spanish Grand Prix is probably the first opportunity for teams to bring a big upgrade to the car during the season.
"The cars have been on the other side of the globe for the first quarter of the year and teams' R&D departments will have been busy coming up with large upgrade packages to bolt on the car for the first time in Spain.
"They will often compromise whole body work packages, so the floor, engine cover, front wings and rear wings, potentially new suspension components and various other bits and bobs. All the teams will have updates and we can see what they all are in a few days."
Red Bull are currently second in the constructors' standings, 97 points adrift of Mercedes.