An option to make the French defender's loan stay a €25million ($28m) permanent switch has expired, Schalke's head of sport Jochen Schneider announced.
Schalke have been out of sorts in 2020, with January recruit Todibo unable to prevent the team going 11 Bundesliga matches without a win.
Speaking about Todibo, Schneider told the Westdeutsche Allgemeine Zeitung on Monday: "The deadline passed yesterday. We no longer have a purchase option.
"Contract extensions are currently not an issue for us. We should rather focus on performance."
Todibo, 20, has made four starts and four appearances as a substitute in the Bundesliga since moving from Camp Nou, playing 363 minutes in the German top flight.