Luciano Spalletti insisted Inter did not "invent" Mauro Icardi's injury after he was left on the bench for the 2-0 win over Benevento on Saturday.
Inter returned to winning ways following a 2-0 defeat at Genoa but Argentina striker Icardi, an unused substitute at San Siro, did not feature for the fourth successive game.
Icardi has been troubled by a muscle problem, but Spalletti, questioned repeatedly about the forward following the victory, was adamant he will be ready for the derby with AC Milan next Sunday.
"He had a problem with his adductor," Spalletti said. "He had a relapse that has delayed the return.
"There are cameras that have recorded the injury, if you want I'll show you the video. It's all recorded. We did not invent anything.
"Of course he will there for the derby."
Icardi has scored 18 goals in 22 Serie A appearances for Inter this season and has been linked with a move to Real Madrid.
Inter's victory moved them third in the table, two points above fifth-placed Lazio in the fight for the Champions League places.