FA defends ball after Guardiola says it is difficult to control

Guardiola compared the ball unfavourably with those used in the Premier League and Champions League after his side's 3-1 fifth-round victory over Plymouth on Saturday, saying it was "not proper".
Earlier this season, Arsenal boss Mikel Arteta was mocked after criticising the Puma ball used in the League Cup. The Gunners lost their two-legged semi-final against Newcastle 4-0 on aggregate.
The Football Association said the ball used in the FA Cup "delivers against all of the testing requirements". "Mitre's Ultimax Pro ball - used in the Emirates FA Cup and all other FA competitions - has been tested in accordance with FIFA testing," said an FA spokesman.
"All footballs in the professional game are required to meet the FIFA Quality Pro accreditation, and this ball delivers against all of the testing requirements.
"Alongside Mitre, we understand that preference is subjective, but we're confident that the ball performs well. With over 350 goals scored in the knockout competition so far, it provides an exciting element to such a competitive tournament."
Guardiola said after his team's victory against Championship strugglers Plymouth: "The ball is not proper, I'm sorry. For many, many years it's happened in the FA Cup or Carabao (League) Cup.
"I know it's a business and they come to agreements, but the ball is not (good). You know how many shots went over the post? Not just Erling (Haaland)'s - look at other games."
City's three goals at the weekend came from 29 shots, of which nine were on target. In their most recent Premier League game, a 1-0 win at Tottenham, they had 12 shots, five of which were on target.
"The Champions League ball is exceptional, the Premier League (ball) is exceptional but this one is not good," said Guardiola.
Adidas balls are used in the Champions League, while Nike balls are used in the Premier League. City, beaten FA Cup finalists last season, have been drawn to play Bournemouth in the quarter-finals.