Leading pair Bayer Leverkusen and Bayern Munich, separated only by goal difference at the top, both have tricky home games, with Leverkusen facing Cologne on Saturday and Bayern taking on Hamburg SV on Sunday.
Although Schalke and Borussia have attempted to dampen down their rivalry off the field, there is little love lost between the players.
Schalke goalkeeper Manuel Neuer gave an interview this week in which he said that Dortmund players had wrongly accused him of elbowing an opponent following Schalke's 1-0 away win in September, courtesy of a Jefferson Farfan goal.
"All the television pictures have shown what happened and what didn't," he told the weekly magazine Sportbild.
"Some of the Dortmund players have damaged my reputation. Their comments were absurd and not nice."
Neuer, expected to be in Germany's World Cup squad, was also angry at Dortmund complaints that he celebrated in front of their fans.
"I had cups of beer thrown at me and was spat at," he said. "But the same people complained that, after the final whistle, I simply raised my arms in front of them."
"Only when these basic rules apply will the clash between Borussia Dortmund and Schalke 04 be what it is meant to be - the Bundesliga's most exciting derby," said their statement.
"Nobody wants a lovey-dovey derby but anyone who wants to turn the rivalry into outright hostility has to be shown where the boundaries lie in no uncertain terms."
A win or draw in Saturday's match would allow Leverkusen to set a Bundesliga record of 24 unbeaten games, overtaking Bayern's tally from the 1988/89 season.
Bayern's coach Louis van Gaal was involved in an angry exchange with a television presenter during a touchline interview after last weekend's draw at Nuremberg.
