Mike McCormack today said he would not resign as coach of the Baltimore Colts as earlier speculated, and refused to comment on reports that club owner Robert Irsay called the plays from the press box in the team's 38-13 loss in Philadelphia on Sunday. It was the Colts' 10th straight defeat.

McCormack, speaking at his weekly press conference, said he has "never quit anything and is not about to start now," despite Irsay's reported play-calling in the second half.

Irsay was seen wearing a headset and talking into the microphone while sitting with the assistant coaches in the press box at Veterans Stadium. Team sources confirmed to United Press International that Irsay made the decisions in the second half while McCormack stood idle on the sideline.

When asked in the locker room, minutes after the game, if he had spoken with Irsay, McCormack reportedly said, "Not since the game."

Beginning in the third quarter, Irsay reportedly told McCormack to bench starting quarterback Bert Jones, then alternate him with backup Greg Landry. Irsay is also said to have ordered an 11-man defensive blitz. The owner could not be reached by telephone yesterday at his offices in Chicago.

McCormack spoke very slowly, carefully choosing his answers to reporters' questions today. He said he talked with Irsay this morning for about an hour, but would not comment on their discussion.

"I have read the newspapers and been told about the things said on radio and television," McCormack said, referring to the reports. "I hope you respect my option on addressing the incident that's on most of your minds. I would like to defer and just say, no comment."

For the next 20 minutes, McCormack politely and thoughtfully answered questions concerning Sunday's defeat, the 10-game losing streak, the week-long controversy between Jones and Curtis Dickey, and his ability to command the players' respect. McCormack also said he and the team have been treated fairly all year by the media.

But when someone tried to sneak in another question about the Irsay incident, McCormack balked.

"I know you don't want to comment on the Irsay thing," a reporter began, "but isn't it unusual for a owner to be sitting up there with a headset on?"

McCormack ignored him, and said unless there were any more questions about Sunday's game, the session was over. He quickly turned from the podium and walked away.

An assistant coach also refused to comment on why Irsay was wearing the headset. Quarterbacks Jones and Landry previously had refused comment.

McCormack's mood was greatly improved over Sunday afternooon, when he appeared shaken while talking in the Colts' locker room. Sources close to the team, the Baltimore News American reported, said he was then considering resigning the job he has held since the start of the 1980 season.

McCormack said his wife -- "a very strong person" -- is helping him get through this period, and that neither of them ever had been through anything like this before.

"I'm not planning to resign," McCormack repeated. "I try to learn from past experiences. And this one is a dandy."