Southampton are understood to have claimed referee Clattenburg verbally abused England midfielder Lallana.
Assistant manager Perez has vowed Saints will not let the developing situation affect their preparations for hosting high-flying Sky Bet Championship side Burnley at St Mary's Stadium on Saturday.
"Our way always is when the game is over, it's time to think about the next game," said Perez.
"So our full focus is to prepare well for the next game, then to ensure we're in best condition for the next match.
"That's our style since we came to England.
"When you are in this business you have to be aware everything is possible.
"We're in the best league, the best environment, in terms of business and media, so we have to respect everything because everyone is proud of this business.
"So it's not difficult for us: we focus and we put our players away from the problems and just think about the football."
Burnley sit second in the Championship standings, and will have in-form ex-Southampton academy striker Danny Ings on show on the south coast in the FA Cup third round on Saturday.
Refusing to go into detail on Saints' complaint to PGMOL, headed up by Mike Riley, Perez said he expects the club to find out more information in the next few days.
"I won't talk about this situation, I prefer to stay away from this and just focus on the game on Saturday," he said.
"This type of situation doesn't help us in this moment, for this game, it's away, and we'll see in the next couple of days what's happening with this.
"I read it this morning; when you are in the games sometimes you can see or hear something, but history has led me to stay away from these things."
- Sports & Recreation