London - Jose Mourinho claimed Tottenham's stars were unsettled during their 1-1 draw against Middlesbrough because the FA Cup ball was too light.
Mourinho's side needed a second half equaliser from Lucas Moura to earn a third round replay after falling behind to Ashley Fletcher's strike at the Riverside Stadium.
But Mourinho suggested the different weight of the FA Cup ball compared to the Premier League one made it difficult for his team to impose themselves on their second tier opponents.
"I think this ball is beach ball. It's too light. I don't think it helps the players. But that's not an excuse," he told BT Sport.
Mourinho wasn't happy with Middlesbrough's goal either, suggesting it would have been ruled out by VAR if the system had been in use.
Only Premier League stadiums have VAR, so Championship Middlesbrough were operating without the controversial reviews.
"Yeah because the Middlesbrough goal is offside. VAR would give (the offside decision)," Mourinho said.
"The referee was not some guy in an office 200 miles away (today)."