The draw against Arsenal means Manchester City are still third in the Premier League table and are now three points behind league leaders Liverpool.
It was the second time Lockyer had collapsed this year.
“It was frustrating when we missed the penalty. We were playing well, and we didn’t get the reward.”
More players are likely to follow, with the situation of Super Eagles’ Kelechi Iheanacho and Wilfred Ndidi sure to attract Nigerian interest.
The England international has been in fine form for Erik ten Hag’s side in recent months.
The apology came after the refereeing governing body admitted Kaoru Mitoma should have been awarded a penalty kick during Saturday’s 2-1 Premier League loss at Tottenham Hotspur.
A statement from the club on Tuesday said the Denmark player was “likely to be out until late April or early May”.
Newcastle United beat Tottenham 2-1 on Sunday to move up to fourth in the English Premier League (EPL).
City are second on the EPL log with 20 points in 8 games, while United are 6th on the EPL log with 12 points in seven games.
Taiwo Awoniyi’s Nottingham Forest lost 3-2 to Fulham at home as League woes continued.
