Jeremy Menez's third-minute penalty had Milan on track in Turin on Saturday, but Kamil Glik levelled late on for the hosts.
Mattia De Sciglio was sent off for Milan late in the first half, hampering their chances of victory.
It means Inzaghi's men are winless in two games since the Serie A break, and he said only hard work could get his seventh-placed team's season back on track.
"Every match is important to us and it’s positive that we’re going to be playing again right away," Inzaghi told a media conference.
"We have the chance to be the Milan side that competed with the best such as Napoli and Roma.
"I don’t know the reasons why, we’re not the same side as we were before the winter break. I only know one way to get back on track: work.
"The spirit is good, as otherwise we wouldn’t be able to defend for 50 minutes without running big risks in defence."
Menez was dragged down for the early penalty and converted, before the game swung when De Sciglio picked up his second yellow card.
And Glik headed in Bruno Peres' late corner to secure a point for Torino.
Inzaghi said it was tough to blame his players after the sending off of De Sciglio.
"We started well, we pressed Torino high up. We should have made it 2-0," he said.
"Once we started to suffer their counter-attacks, we dropped back a bit too much.
"Then, we went down to 10 men and from then on I cannot blame the players for anything.
"We conceded a goal from a dead-ball situation and when you concede from a corner kick it is never a positive thing."
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