Newcastle manager Rafael Benitez believes Aston Villa's struggles prove Championship life can be difficult for former Premier League clubs.
Both sides were relegated last season but Villa have struggled to find form, while Newcastle are top.
"They have proved it's a difficult division," Benitez told BBC Radio Newcastle.
"It is not easy to go down and go up first time. It is important to have everyone working together," he added.
Newcastle host Aston Villa on Monday night, with the two sides meeting at St James' Park for the first time out of the top flight since 1938.