Liverpool's manager, Brendan Rodgers, has been asked for "his observations" following his recent comments about the referee Lee Mason, the Football Association has confirmed.

Rodgers questioned the decision to appoint Mason to his side's Boxing Day Premier League defeat at Manchester City because he is from the Greater Manchester (Bolton) area. The Liverpool manager had been frustrated by a number of decisions made by Mason and his assistants during the 2-1 defeat at the Etihad Stadium.

An FA spokesman said: "We have contacted Brendan Rodgers to seek his observations in relation to his post-match comments made following the game at Manchester City."

Rodgers has until 2 January to respond to the request and the FA will then consider whether any further action is necessary. Rodgers could be warned as to his future conduct or hit with a financial penalty if found guilty of any charge.

The Northern Irishman feels he was making a valid point about where Mason is from and indicated, as he met the press to preview Sunday's game at Chelsea, that he would stress that to the FA.

"I was only speaking honestly after the game", he said. "I think the FA and the Referees' Association know perfectly well I am someone who engages in supporting the referees. I am not one that berates referees at all after games, I always respect them. I ask my staff to be respectful.

"In terms of geography, I certainly wasn't questioning the integrity of referees. It was more the logic of it in terms of having a referee from that part of the world refereeing a game in Manchester. I wouldn't suspect that Mike Dean, from the Wirral, has refereed many games for Liverpool over the years." Dean, incidentally, was dropped from officiating at the 2006 FA Cup final between Liverpool and West Ham for geographical reasons.

Rodgers, formerly manager of Watford, Reading and Swansea, believes he has maintained high standards of behaviour throughout his career and insisted his post-match comments were delivered in a calm, considered manner.

"I think if you look at my record since I have been a manager, I have never had any indiscretions whatsoever," Rodgers continued. "I never get involved in that way of working, I don't play games.

"I am sure that is something they will look at but I will always fight my corner. That is the type I am and always will be but I respect the authorities. We will see what happens."

Rodgers was certainly not willing to backtrack on any of his complaints about the decisions he had issues with.

Liverpool's primary source of frustration was an incorrect offside call in the first half when Raheem Sterling was clean through. Luis Suárez was also denied a free-kick on the edge of the area and a penalty after clashes with Joleon Lescott later in the game. Philippe Coutinho had given Liverpool a 24th-minute lead before Vincent Kompany and Älvaro Negredo replied for Manchester City before half-time.

Rodgers said: "I think it was continuous throughout the game – the decision-making being poor. I think there was evidence of that."