Newcastle United fullback Kieran Tripper felt they were flat for their Champions League defeat at home to Borussia Dortmund.
Felix Nmecha struck the only goal of the night for the visitors.
Trippier later said: "We weren't anywhere near our best. We pushed them more in the second half, but we know we can do a lot better.
"Every game's important and our next game is Wolves.
"We need to switch our attention back on the Premier League now."