Mbolhi was instrumental in forcing the game to extra time on Monday thanks to an impressive display in goal, but he was not able to stop Germany reaching the quarter-finals with a 2-1 win after 120 minutes.
"We're very disappointed because we felt we had a chance. Fitness wasn't the decisive factor," Mbolhi is quoted as saying by FIFA.com.
"We owe it to our coach that we made it into the round of 16. We'd like to thank him for everything he's done for and with the team."
Germany will now face France in the quarter-finals following their win over Algeria.