The Catalan giants' current coach Ronald Koeman is facing a highly uncertain future at Camp Nou amid growing tensions with club president Joan Laporta.
Martinez himself has played down reports linking him with the manager's job at Barcelona, but the former Everton and Wigan Athletic coach continues to be linked with the post nonetheless.
According to Sport, Martinez can terminate his contract by forking out £1.5m to Belgium, but Barcelona would be the ones to cover the costs should they make a formal approach.
Martinez is expected to remain in charge of Belgium until the conclusion of the 2022 World Cup, but his future with the Red Devils beyond that point is unclear.
Meanwhile, Koeman has less than 12 months left to run on his Barcelona contract, although Laporta has admitted that his patience with the Dutchman is wearing thin.