Fettis has one cap to his name, that coming in 1998 in the 3-0 Euro 2000 qualifier against Turkey.
With Manchester United's Roy Carroll dropping out the squad, boss Lawrie Sanchez called on Fettis as back up for Birmingham's Maik Taylor.
Fettis will travel to Tallinn and train with the squad. However it is unlikely the stopper will feature in the game.