The derby finished at a 0-0 stalemate on Sunday.
“I have to compliment my lads, as it wasn't easy in the circumstances, but we did well to react to Thursday's Europa League exit," Inzaghi told Mediaset Premium.
“With a little more sharpness in the final third, we could've won the game, but apart from the final 10 minutes down to 10 men and that Bruno Peres effort, we weren't particularly threatened.
“Up until Stefan Radu's red card, we were right in there, but we played on Thursday evening and only returned home on Friday, so it was inevitable we'd tire towards the end.
“Thursday was a stain on our season, but that cannot cancel out nine great months. We won the Italian Super Cup, reached the Coppa Italia semi-final and only went out on penalties, reached the Europa League quarter-final.
“We're still in third place and with a different deflection on that Adam Marusic chance, we could've won the match.