BALTIMORE Running back Jeff Logan has his head on straight, as they say these days, because he has an 18-inch neck.

That would not be unusual for a graduate of Woody Hayes' charm school, except that Logan is only 5-foot-9 and 190 pounds.

"I think I am big enough," he said after the Baltimore Colts finished practice yesterday. "In the Big 10 Conference you play against some of the biggest players in the country. The main thing in pro ball is to stay well."

Another fuzzy-cheeked Buckeye who came to the Colts looking too young and undersized, Tom Matte, served Baltimore well as "the Garbage Man." He did a bit of everything, mostly as a running back.

Logan resembles former Colt running back Don (Bowling Ball) Nottingham. Logan has a 44-inch chest, but a 32-inch waist, obviously sculpted with the specialized use of weights.

The breeding and the breeding place portend good fortune for him and the Colts. He is the son of Dick Logan, who played tackle for the Green Bay Packers in 1952-53, and is a native of that rich football lode, Canton, Ohio, where Jeff would like to end up enshrined in a certain hall of distinction.

Curiously, Logan has three younger brothers and a father over six feet, and his mother is of "average" height, he said. He can't account for his size.

As a junior he thumped out 1,248 yards in 218 carries, or more than five yards a rush. An ankle injury cut his production to 606 yards in 107 tries last season. But Hayes said, "Without Logan the Buckeyes would have been a mediocre team."

Hayes is not given to excessive compliments. In fact, Logan says the big difference between college and pro ball is that "Woody Hayes 'vocalizes,' if you will, when he coaches."

Asked to be specific, Logan said, "He was loud. It was all a teaching experience on the field. Here (at the Colts' Goucher College campus training camp), it is quiet.

"Hayes would take you to the edge of frustration and fear of failure and then bring you back. Here, it is assumed you already have been taught many things."

Logan was not selected until the fifth round and he said there is more of a feeling of insecurity in pro ball.

"It's a cutthroat thing," he explained. "In college, once you got a scholarship you were secure in the knowledge that you at least could get an education.

Logan acknowledged that he knows some Ohio State running backs, such as Bob Ferguson, didn't make it in pro ball, but he pointed out that the Colts had good fortune with other OSU graduates such as Matte, Hall of Fame offensive lineman Jim Parker and current linebacker Stan White.

Asked about his anxieties so far, Logan said, "I think I am doing well."

That was quite an admission, he indicated. He said that four years Hayes discouraged players from talking to the media.

"That changed some after Cornelius Greene and Archie Griffin and a couple of others showed they could handle themselves well," Logan said. "I was a public relations major at Ohio State, so I know both sides of the picture. Hayes used to advise not to say anything negative about our teammates or about our opponents."

Logan is "doing well," judging by Ted Marchibroada's careful remarks. "He is our closest hope for the special teams and as a fifth running back," the coach said. "He has good hands and we hope he can run back punts and kickoffs for us and maybe go down under kicks.

"That's where we need to improve. We had three kicks run back for touchdowns last year. We had the number three offense in the AFC. We have some room for improvement on defense, but the special teams are our main concern."

The Colt kicking game was satisfactory yesterday with David Lee punting and Toni Linhart place-kicking. Lee averaged only 37.4 yards in 1977 but he kept the punts high. His longest kick was 59 yards and 19 times he punted the ball dead inside the opposition's 20-yard line.

Linhart was 17 for 26 in field goal attempts and 32 for 35 in extra points to finish second in AFC scoring.