"It's difficult to give an explanation after these situations. The team played thirty minutes of high level, in complete control of the match," Sarri told Sky Sports. "It's not a tactical problem".
Lazio scored the opening goal through Ciro Immobile's fierce right-footed drive. However, after the break Lecce staged an impressive comeback with Gabriel Stefezza's 57th minute strike and Lorenzo Colombo's 71st minute winner.
The result left Lazio fifth in the standings with 30 points from 16 games, while Lecce are 13th with 18 points.
"If we don't beat Lecce it means that, perhaps, we are inferior to what we think we are. They upped the tempo when we allowed them to, when they saw us vulnerable they were very good at biting and tearing us apart," Sarri added.
Lazio went into the World Cup break on a losing note after being hammed 3-0 by Juventus, which Sarri described as inconceivable, and their fortunes failed to improve when action resumed in the league seven weeks later.
"I find it difficult to even talk about it. If it were up to me we would always play, this break has been a blasphemy and global football has gained nothing from it," the manager said.
