The North East outfit have now drawn five out of their six Premier League matches, with the Uruguayan at a loss to explain their winless start.
"What do we have to do to win a football game? We did everything. We were the better team 11 versus 11. We created chances and we were the team looking to have that winning goal," BBC Sport quotes him as saying.
"When they had a man sent off it was even more like that but we can't put the ball in the net and take advantage of our game. If we were terrible and couldn't pass the ball or create chances I would be worried but the way we played today I am calm.
"I will look to prepare to make sure we win the next game."
The result leaves Sunderland in 15th place in the Premier League table.