After Williams removed its controversial solution for the 'Coanda'-effect exhaust late last week, heads are now turning in Caterham's direction.
Williams' move to remove the solution reportedly followed the FIA's Charlie Whiting telling team designer Mike Coughlan at Jerez that he deemed it illegal.
But while Williams' solution attempted to find a loophole in the regulations, Coughlan said recently he thought Caterham's similar approach is "clearly not allowed".
A Caterham spokesman said: "We are continuing to evaluate a range of options at the pre-season tests as per our normal programme."
But the team's new Dutch racer Giedo van der Garde is not so sure that means Caterham will remove the solution.
"I am told that it is legal, so I am not worried," he is quoted by the Dutch magazine Formule1.
"I expect to find the same exhaust on the car in Barcelona."
The third and final four-day pre-season test begins on Thursday.
Motorsport.com
Circuito Permanente de Jerez – February 5 - Giedo: 1:21.915 - 64 laps
