Douglas Maicon had given them the lead at half-time, but Claudio Pizarro equalised in the second half.
"I think Inter played well and all we were missing was the result. We had many chances to score the winner, but Werder got the point," said Zanetti.
"We should've sealed this up earlier, but wasted a lot of opportunities. At least the fact we create so many chances shows the team is in good shape.
"We need to work on the defence and everyone being more concentrated. It's just a shame about the result, but we are all looking forward to the next game."