The Poland international is a top target for Manchester United and tipped to move to Old Trafford in the summer.
"He fired us to the championship last season, so it would be important that he stays," Weidenfeller said. "He should offer a positive gesture to the club so they can get around the table again.
"There are many players who have been unfortunate in retrospect when they leave Borussia Dortmund. Lucas Barrios is one of them. Therefore Robert Lewandowski knows exactly what he has at the club, especially with this team.
"He needs the other guys who feed him with chances, so he can get his goals."