Bayern, who lie five points behind Bundesliga leaders Borussia Dortmund, have one foot in the semi-finals of the Champions League after a 2-0 first-leg last-eight win at Marseille on Wednesday night, with Real Madrid likely opponents for a place in the final.
They are also in the German Cup final, where they face Dortmund in May, with Nerlinger worried that fatigue could impact upon their chances.
"We will need to reach our limits for the next four or five weeks," Nerlinger said. "That will be a mental as well as physical challenge.
"We are in the final stretch in all competitions and the team is motivated."
Bayern, who have won their last seven matches and scored six or more in three of them, face Nuremburg in a Bavarian derby on Saturday.