The Reds lost 2-0 away to Middlesbrough at The Riverside on Saturday.
The Spaniard told Sky Sports: “Before the game it was very difficult, now it is more difficult.”
“Clearly you have to take your chances if you want to win these games,” added Benitez.
“In the first 30 minutes we had five chances and we did not score a goal.
“Clearly it has been a problem this season, and today it was the same.”
