Everton must decide whether they trust manager Marco Silva before making a decision on his future, according to Manchester City manager Pep Guardiola.
Despite a large outlay on transfers over the summer, Silva has guided Everton to just three wins in their last 12 Premier League games to leave them ninth in the table ahead of their clash with City on Wednesday.
Guardiola guided City to the Premier League title and record points total in his second season in England, but his critics have often pointed to the Spaniard's heavy spending in the transfer market as a key factor behind his success.
"The people don't know how difficult it is to create the teams," Guardiola said on Tuesday. "The people believe I buy three or four players, a new manager, and everything fits perfectly immediately. Sometimes it takes time.
"My advice... if they believe in the project, if they believe in him, they have to move forward with him, but nobody assures you a new manager is going to better.
"It's difficult to create, to build something. You need time, it takes time. So it depends if they trust (him) or not."
Everton went to great lengths to bring Silva to Goodison Park and were threatened with legal action by his former club Watford for their initial attempts to prize him away from their Premier League rival.
After finally being appointed Everton manager last summer, Silva signed Richarlison, Yerry Mina and Lucas Digne at significant expense and brought in Kurt Zouma and Andre Gomes on loan deals.
Inconsistency has been a major problem for Silva, with Everton only having strung together successive victories on one occasion this season.
A chastening 3-1 defeat at home to Wolves on Saturday ramped up the pressure on the Portuguese, but club owner Farhad Moshiri has said he will "hold his nerve" over Silva's future.