Bayern Munich boss Carlo Ancelotti has criticised the Chilean FA for their treatment of midfielder Arturo Vidal during World Cup qualifiers.
Volland, 24, joined Leverkusen from Hoffenheim in the summer for a club-record fee of around €20 million.
Franck Ribery signed a contract extension until the summer of 2018. Like Robben's, his existing contract had been due to expire next summer.
Schalke want to show RB Leipzig "what honest and proper Bundesliga football is about" when the two in-form sides clash at Leipzig's Zentralstadion.
Ribery said he believed the summer change in coach had also been a pivotal factor but added that he had formed a close bond with Carlo Ancelotti.