Royal Blues have reportedly failed to land Trapp, but still have three other options lined up as they search for Manuel Neuer's replacement.
The Champions League semi-finalists have been close to a number of candidates, but suffered a setback on Wednesday when it was revealed that their bid for Kaiserslautern's Kevin Trapp had failed.
Schalke made a €7 million offer for the 20-year-old, which 1. FCK rejected, according to Sport1. Kaiserslautern are said to value their No. 1 at around €9m, and it appears that neither club is interested in making concessions to force a deal. The Red Devils have no need to sell their rising star, who is under contract until 2013.
Schalke can now look to other options. Genk's Thibaut Courtois is a slightly less expensive alternative who has attracted the Royal Blues' attention, according to Sport Bild.
The Belgian is said to cost around €8m, and despite being just 19 years of age, he made his professional debut two years ago. With his contract set to run until 2014, Genk will be in a good position to retain Courtois, or to stand firm on their demands.
In addition to Trapp and Courtois, Schalke have also been closely linked with Hannover's Ron-Robert Zieler, and Frankfurt's Ralf Fahrmann.