The in-demand RB Leipzig defender has been nursing a groin injury and was ultimately forced to pull out of the squad, while his World Cup partner Dejan Lovren has now retired from international duty.
With no Gvardiol or Lovren to protect number one Dominik Livakovic, another highly-rated defender in Josip Sutalo should get the nod alongside Sassuolo's Martin Erlic, although 100-cap Domagoj Vida is another option.
Josip Juranovic and Borna Sosa should win their head-to-heads with Josip Stanisic and Borna Barisic to start in the wide areas, and despite his recent exertions in the Champions League final, Marcelo Brozovic will act as Dalic's midfield screen.
Captain Luka Modric is poised to win his 165th cap for Croatia in the engine room alongside Brozovic and Mateo Kovacic, whose future remains the subject of intense speculation amid talk of a move to Manchester City.
Needing just one more goal to hit the 34-mark and become Croatia's outright second-highest scorer of all time, Ivan Perisic starts on the left, as Atalanta BC's Mario Pasalic occupies the other flank.
The duo will expect to be supporting Andrej Kramaric in the wake of Marko Livaja's withdrawal, which came after he was subjected to insults from a few supporters who turned up to watch a recent training session.
Croatia possible starting lineup: Livakovic; Juranovic, Sutalo, Erlic, Sosa; Kovacic, Brozovic, Modric; Pasalic, Kramaric, Perisic