Newcastle were on the wrong end of a five-goal clash against Leicester City on Saturday which condemned them to their sixth defeat in seven games.
Perez was on to try to force a victor for the hosts but tore back desperately as Leicester broke in the 86th minute - his desperate challenge on fellow substitute Shinji Okazaki succeeding only in diverting the ball past helpless goalkeeper Karl Darlow. "What I can say is the players, they put in an effort on the pitch, but still we have to improve if we want to get three points in these kind of games", Benitez told reporters.
Newcastle head into the game in miserable form, as they lost 3-1 at Chelsea last weekend - despite taking a 1-0 lead - to make it just one point in the last six games.
"The way we concede, for confidence, it is hard but we have to keep going".More news: Missed Field Goal Seals Army's 14-13 Win Over Navy
By contrast, things are looking up for Leicester manager Claude Puel.
"It's a good result for the last three games but it's important to consolidate our position in the table and continue this work", Puel told BT Sport. The first half was good but the beginning of the second half was hard.
"The second goal gave us the lead, but it was hard, but a draw would have been hard to accept, so my team deserved the third goal with a fantastic and positive attitude".
"It's a good win away and we go next game to Southampton, a hard game too and it will be important to recover", Puel added.