George Steinbrenner pronounces Yankee third baseman Graig Nettles "in the twilight of his career"--while the two who, in turn, succeeded Nettles at third in Cleveland fear career lights out before they make it to a World Series.

Yes, Buddy Bell and Toby Harrah.

In New York, owner Steinbrenner has Rick Cerone, the catcher, preparing to platoon with Nettles at third and "no joke." Big George says of Nettles, 38, "There comes a point in everybody's life . . . where the body can't do it anymore." But, "I still wouldn't mind having him as my third baseman in the World Series."

In Cleveland, hear Harrah rap the Indians' front office: "Check the roster and tell me if you think we can win a pennant. Eleven guys up from the minors, that's a lot of guys making the minimum. It seems . . . one eye on the pocketbook, one eye on the gate and one ear on the W andcan do the job. Why get rid of people who are committed (like Don Zimmer)? I can't wait until my six (contracted) years are up."

Yes, the Johnson replacing Zimmer is the Johnson replaced by Zimmer at Boston in July 1976--and who, moving up from Zimmer lieutenant, says, "I have no magic wand I'm gonna wave and say all this will change" . . .

Promoters Don King and Bob Arum clash again--now over Roberto Duran. Wednesday, King said Duran would fight Tony Ayala Nov. 19 on NBC prime-time TV; yesterday, Arum said he had Duran signed to challenge for Davey Moore's WBA junior middleweight title, same date, same network. An NBC spokesman hedges, "Duran and Ayala will fight Nov. 19 in prime time, but maybe not against each other." Meantime, litigation looms.

National Basketball Association, which promised hardball when it hired a labor specialist, is in with an unfair labor practice charge against NBA Players Association for refusal to bargain on a proposal to "moderate" player salaries . . . Owners of Mets, Cardinals and Astros, evidently bent on ending Bowie Kuhn's tenure, affirm call for special NL meeting Aug. 17, eve of owners' regular joint session.

Recovery chart on Astros' J.R. Richard: 3-0, 1.91 ERA, 19 strikeouts in 33 innings at Daytona Beach; one more Class A start, Monday, then to AAA Tucson . . . Claude Humphrey, old pro defensive end reporting to Eagles' camp, finds knee surgery required; so retires, again . . . About to be official holdouts: Cowboys' Ed Jones, Bills' Joe Cribbs . . . Providence College had Jeffrey Fogelson, Georgetown associate a.d., one of three finalists for athletic director before picking Lou Lamoriello, Friars' hockey coach . . . Ken Haines, Virginia Tech director of public affairs, to be a vice president at Raycom, new ACC telecasters; he assembled Tech's 70-station radio network.