Newcastle United manager Rafael Benitez lamented familiar mistakes after his side's winless run continued with a dramatic 3-2 defeat at home to Leicester City.
Ayoze Perez was brought on with the game locked at 2-2 - Dwight Gayle having equalised after Leicester duo Riyad Mahrez and Demarai Gray overturned Joselu's early opener - but the Newcastle forward did not have the intended impact.
Tearing back to defend after the hosts were picked apart on the break, a desperate challenge from Perez on fellow substitute Shinji Okazaki only resulted in him diverting the ball past goalkeeper Karl Darlow and into his own goal.
"It was another mistake," Benitez told BBC Match of the Day, with his team two points above the Premier League relegation zone after losing six and drawing one of their last seven outings.
"We have to learn and have more experience and manage it better.
"We have seen two or three situations with the same kind of goals. It is sometimes a lack of experience.
"The way we concede, for confidence, it is difficult but we have to keep going. We have to improve the things we are not doing well at the moment.
"These kind of mistakes, you cannot make in the Premier League and we are doing it week in, week out."
By contrast, things are looking up for Leicester manager Claude Puel.
The Frenchman inherited a side with two wins from nine games when he was installed as Craig Shakespeare's permanent replacement at the King Power Stadium.
The Foxes are now up to eight in the table having taken 14 points from 21 on offer under the former Southampton boss, with their only defeat in this period against Premier League leaders Manchester City followed by three consecutive victories.
"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.
"It was a difficult game and not our best game because we were up and down. The first half was good but the beginning of the second half was difficult. We scored a terrific second goal and came back after we conceded again with a fantastic spirit.
"It's amazing to see my players with this positive attitude."
Such positivity was not associated with Puel's Southampton during his one-season reign last term, despite guiding the Saints to the EFL Cup final.
That reunion is up next in midweek.
"It's a good win away and we go next game to Southampton, a difficult game too and it will be important to recover," Puel added.