The defending US Open champion has been sidelined by an arm injury since December, and speaking on Monday he admitted that he may not be ready for the testing Davis Cup format.
"I've been out for seven weeks already and will be sidelined for at least another two, hence playing best-of-five sets matches straight away would be difficult," Cilic told reporters.
"My recovery is not as speedy as I expected it to be, the latest scan has shown an improvement and I am working hard to get back but I've had to cancel my participation in the Zagreb Indoors, Rotterdam and Delray Beach.
"If (world number one Novak) Djokovic doesn't play for Serbia we could win with a bit of luck but even if we don't, one should remember that forming a competitive squad is a process."
The tie will take place on March 6-8 in the Serbian city of Kraljevo.