According to Spanish newspaper El Mundo Deportivo, Barca sporting director Andoni Zubizarreta contacted Chelsea first regarding Courtois, who was on loan at Atletico Madrid.
Chelsea rejected that approach immediately as they view Courtois as an important member of the team going forward, so later in the month of May Barca returned with an enquiry for Petr Cech.
Chelsea officials also turned down that approach, leading Zubizarreta to pull the trigger on the deal to bring German keeper Ter Stegen to the Nou Camp.
Barca were on the look out for a new goalkeeper following Victor Valdes's decision to leave the club at the expiration of his contract this summer.
The report goes on to say that Barca suspect that Jose Mourinho had an important role in turning down both offers - the Chelsea boss has a long running rivalry with the Spanish giants and Barca believe he refused to do business with them on that account.
Ter Stegen is not the only goalkeeper Barcelona have signed this summer, as they've also completed the capture of Real Sociedad stopper Claudio Bravo. Bravo has impressed in goal for Chile at the World Cup.