Antonio Conte feels Inter's derby victory over Milan took away a lot of "nervous" energy as his side fell to a limp Coppa Italia semi-final first-leg loss at home to Napoli.
The Nerazzurri fought back to defeat their rivals 4-2 in a barnstorming Serie A encounter on Sunday.
It was a different story on this occasion, though, as Inter struggled to get out of second gear and succumbed to a 1-0 loss thanks to Fabian Ruiz's excellent second-half strike.
Speaking to Rai after the game, head coach Conte said: "The derby took away a lot of energy, especially nervous.
"I made five changes from Sunday to bring in fresh legs, but Napoli beat Juventus, Lazio and Liverpool this season, so that means they've got quality there.
"I'd say that, after Juventus, Napoli have the most impressive squad in Serie A.
"Gennaro Gattuso was smart to sit back, wait and go on the counter. We had the chances and it would've been a fair result if we had played out a draw.
"When you're up against defensive teams like this, you have to move the ball around faster and create spaces.
"We are at the start of this journey, so if some think we are at the same level as a side that was at the top for many years, then I say we're a long way off and have to use these defeats to improve."
Christian Eriksen was again only among the Inter substitutes, with Conte explaining the Denmark playmaker is still finding his best form after being in and out of Tottenham's team.
"He is certainly a player of quality, he needs to rediscover that intensity, seeing as he hasn't played much in the last six months," the ex-Italy boss said of Inter's January arrival.