Manchester United boss Ole Gunnar Solskjaer believes Liverpool manager Jurgen Klopp is trying to influence referees when talking about his team's penalties.
United were given a total of 22 penalties in all competitions last season, more than any team in Europe's top five leagues in the previous five years.
It included four in two games against Chelsea, and manager Frank Lampard raised the issue before his team beat United 3-1 at Wembley in July.
Solskjaer blames that for referee Mike Dean's refusal to award a penalty for Kurt Zouma's challenge on Anthony Martial before half-time - even though Bruno Fernandes later scored United's consolation from the spot - and is wary of officials being swayed by his rivals.
"I can't talk on behalf of other managers, why they say things like this," said the United boss, when discussing Klopp's claims.
"Obviously I felt it worked last year in the FA Cup semi because Frank spoke about it. We had a nailed-on penalty that we should have had and didn't get, so maybe it's a way of influencing referees.
"I don't know but I don't worry about that. When they foul our players it's a penalty. It's just when it's inside the box."
