The Magpies are juggling a European campaign with domestic matters and while they are in the last 32 of the Europa League - due to play Metalist Kharkiv - they are struggling in the league.
"We've made mistakes," Pardew told a press conference.
"The squad was probably too small. We broke the team up in those Europa League games, which probably took some momentum away.
"Talking to Premier League managers, we're all of the same opinion.
"I don't think there's anyone who would go against my opinion that this competition is not great for Premier League teams. There are too many games put into a very competitive, tough league.
"I think our league physically is definitely the toughest. I wouldn't say it's the best, maybe.
"You could argue that La Liga or Ligue 1 in France, but our league is very physical and it takes its toll. That is the nature of this Europa League.
"We are talking about that because of the draw but it's some way off that game [against Metalist] and it has no impact where we are right now. We have Premier League games that we want to win."
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