The former Bristol Under-21 centre has been thrown in by the Castletown club for the first leg of their PARKER PEN SHIELD semi-final at Petrarca Padova this Saturday.
It is the first time Caerphilly have reached the last four in Europe but they have been forced to turn to 22-year-old Higgitt after first choice Sam Cox underwent surgery on a shoulder injury.
"It was a big blow to lose Sam because he has been performing so well for us and has really come on," said Caerphilly coach Mark Ring.
"He could be out for the rest of the season so we had to call in Rob as a replacement. Unfortunately we are going to have throw him straight in because of other injuries."
However Higgitt will have a few familiar faces around him when he lines up for the Welsh side with fellow former Bath University team-mates Nick Rouse and Joe El-Abd both in the squad.
Injuries have also ruled out veteran skipper Chris Ferris (knee) and outside-half Luke Richards (ankle) from the side though Tongan wing Taumaholo Taufahema (knee) and scrum-half Andrew Chiltern (concussion) have both been passed fit.
Caerphilly have beaten two Italian sides - Rovigo and Parma - on route to the semi-final though Padova, runners-up in the Italian championship, are expected to field Italian pair Mirco Bergamasco and Marco Bortolami who both played in the shock Six Nations victory over Wales.
Caerphilly: S Tuipulotu; G Lewis, R Boobyer, R Higgitt, T Taufahema; J Thomas, A Chiltern; L Manning, F Vunipola, D Sweet, D Davies, P Jones, J El-Abd, M Workman, S Grainger. Replacements: G Liddon, T Carless, N Rouse, A Williams, g Jones, F McLoughlin, R Howells.