Midfielder Stuart Armstrong has been called into the Scotland squad after attackers Lewis Morgan and Che Adams pulled out.
Adams was a major doubt due to a thigh injury which saw him miss Torino’s city Derby with Juventus at the weekend.
Head coach Steve Clarke had stated when he named his squad for the Nations League double-header against Croatia and Poland that he was satisfied with the number of forwards in the squad should Adams fail to make it.
Wideman Morgan, who can also play up front, is also listed as having withdrawn. The New York Red Bulls winger was voted Major League Soccer comeback player of the year this week after ending the campaign with 13 goals and seven assists.
Armstrong has been called up for the first time since the European Championship finals after delivering two goals and two assists in 10 appearances for Vancouver Whitecaps.
Tommy Conway, Lyndon Dykes and Lawrence Shankland are competing for the centre-forward role for Friday’s Hampden clash with Croatia. Scotland finish their A1 campaign in Warsaw three days later.