"I'm just a country boy from Mississippi who went to Alabama and played a little bit at Baltimore," said Ray Perkins upon introduction yesterday as the 11th head coach in the 54-year history of the New York Footbal Giants.

Perkins, 37, caught passes from Joe Namath, Ken Stabler and John Unitas along the way to fulfilling "aspirations to be a head coach since high school and seriously since my sophomore year in college" -- and, in making good as San Diego Charger offensive coordinator, whence he moves to the Meadowlands, he says he took the cue from his old Colt batterymate:

"Unitas always said take what the defense gives you."

Perkins reportedly received a three-year contract -- although what does that mean these days? -- and in Fort Lauderdale, here came Billy Martin to press George Steinbrenner for a two-year, 1980-81 commitment in writing as Yankee manager-again. Martin had a contract through 1979 when eased out as manager last July 25 so Bob Lemon could lead the team out of the woods and win the 1978 World Series as Martin had the '77 ball of wax -- now, says Billy the Kid: "I do have a verbal contract (to manage in '80 and '81), but I want to firm it up and it will be definite. If I'm not coming back, let's find out." Naturally, he brought his agent along.

It's a one-year contract for Larry Csonka, 33, to don Dolphin No. 39 and try to play fullback again for the team of his glory days. Coach Don Shula ventured he feels Csonka "has a lot of football left in him -- there hasn't been a lot used up in the last four years." If he sticks, he gets to add to Miami club record totals of 5,900 yards rushing, 44 touchdowns he amassed 1968-74.

Bad heat in Oklahoma City: Cecil Samara reaped national publicity for driving his 1923 Model T "Big Red Rocket" and miniature Boomer Sooner trailer to Oklahoma football games, there to sport custom-made red and white suits and flash the "BIG RED" emblazoned on his front teeth as Sooner fan numero uno. Bad news, fire from a faulty kitchen range the other day gutted his home, destroying Sooner football mementoes collected over more than 20 years and stored in, what else, his Red Room. Investigators placed damage at $65,000; Samara lamented, "All the money on God's earth" can't replace the loss -- all the way down to a football from All-America Tommy McDonald found flattened on the floor, its hide ruptured by the blaze.

Certified as one of the country's 10 fastest masters swimmers: Jim Kalas, president of the Nautilus Aquatic Club that does its stuff at the Downtown D.C. YMCA; with 2:33.37 in the 200-meter freestyle (fourth in the land) and 3:33.19 in the 200 butterfly (10th)... Again No. 1 nationally in men's 70-and-over singles and doubles tennis, says USTA: Frank (Buddy) Goeltz of Rockville, tennis pro emeritus at Columbia Country Club.