The Brazilian's tactical failings were exposed again as his team collapsed to a 5-2 defeat at home to Schalke 04 in Tuesday's Champions League quarter-final, just as they were in the 3-0 Serie A defeat to neighbours AC Milan four days earlier.
"The first thing we need is to rest our heads," said Leonardo, looking surprisingly relaxed after the game. "We have a very mature squad and we need calm and rest. we need to use our energy on the pitch."
With Lucio suspended, Leonardo repeated Saturday's makeshift central defensive partnership of Andrea Ranocchia and Cristian Chivu, with equally disastrous results.
Last season, Inter beat Chelsea 3-1 on aggregate in the last 16 and overcame CSKA Moscow 2-0 in the quarter-finals, the four games producing fewer goals than Tuesday's extravaganza which Schalke coach Ralf Rangnick said could have ended 10-5.
It sparked criticism from Gazzetta della Sport, coming after the previous round's 3-3 aggregate draw with Bayern Munich when a last minute away goal sent Inter through.
"The sink or swim philosophy which saved the title defence in Munich has this time mis-fired," said Gazzetta, harking back to the days of 'Special One' Mourinho.
"The fact is that the midfield gave their opponents too much room to play in, something that would never have happened in Mourhino's days.
"Mourinho always said that the Champions League is a question of details. The impression is that not enough attention has been paid to them in the absence of the Portuguese guru."
"I don't like to make excuses," said Leonardo. "All is not lost, we are five points behind and we have seven games left.
"We have to change this situation. We lost two important games but we must stay together and try to forget these heavy defeats."
"We have to stay calm," said Inter captain Javier Zanetti, echoing Leonardo's sentiments.
"Calm so that we can understand what the problems were and then start again, as we have many times in the past. We'll do it again this time.
