Celtic will play Israeli side Maccabi Tel-Aviv or Cluj of Romania in the Champions League third qualifying round should they overcome Nomme Kalju.
The Scottish champions host the Estonians in the first leg on Wednesday while Cluj host Maccabi following Monday's draw.
If Neil Lennon's side lose, they drop into the Europa League qualifiers.
In that scenario, they will play the winners of Shkendija of Macedonia and Luxembourg's F91 Dudelange.