The Croats are warm favourites ahead of their first leg in Reykjavik on Friday, although head coach Niko Kovac has already been forced into a change - with Dnipro Dnipropetrovsk defender Strinic unavailable due to an abdominal injury.
He is replaced in the squad by Panathinaikos left-sided player Danijel Pranjic, with the 31-year-old expected to slot into Kovac's back four.
Pranjic last appeared in national colours in Croatia's 4-2 loss to Switzerland in August 2012.
Strinic's injury is in addition to doubt surrounding the fitness of striker Ivica Olic, although Kovac was quick to dismiss the query on the Wolfsburg front man.
"The situation is complicated with Strinic and we won't know the extent of his injury before a scan but Olic should be fit for the return leg because it looks like a strain rather than a torn muscle," Kovac said.
"Our first priority in Iceland will be to score an all-important away goal and we also want to look like a decent team," Kovac said.
