Italy coach Luciano Spalletti praised the never-say-die attitude of his players in rescuing a point with a 98th-minute equaliser against Croatia on Monday to book a European Championship round-of-16 place, but said there was much room for improvement.

Substitute Mattia Zaccagni earned the 1-1 draw in Group B as holders Italy set up a clash with Switzerland in Berlin on Saturday but Spalletti seemed to take offence at several questions in the post-match press conference in a fiery display.

"We deserved to go through tonight in terms of what we produced out there. We were a bit soft at times during the game, we did not necessarily play our best football," the former Napoli coachsaid.

"But it was hard to make it through this group. Spain are brilliant, Croatia are excellent. When you drop below the minimum standards like we did in the first half, it is because we feel the pressure of how important the game is.

"Because otherwise it is not possible (to play so poorly). But thus far everything they (the players) have done (at the Euros) has been getting better from my perspective."

He suggested his players needed to improve physically ahead of the knockout rounds.

"Whenever there is a challenge or a 50-50, we don't win any. It is not a technical question, it comes down to experience, getting into these physical challenges and being willing to do the dirty work. We need to improve on that score."

Spalletti was, however, pleased his side were able to keep their shape as they ended the game with six attacking players in a desperate search for an equaliser.

"The players who came off the bench were immense, those that played for the last 10 minutes were crucial. They kept that shape despite the fact we were ultra offensive. We knew we could not concede a second or third goal, but we also had to attack."

He challenged his team to cut out the individual errors that have proved costly in recent games.

"Today we were timid, but we need to do more," Spalletti said. "We have players who have the quality to play these games on an equal footing, but sometimes we make trivial mistakes."