Dave Cowens was supposed to start his second day today as assistant general manager at the New England Harness Raceway in Foxboro, 20 miles away from the Boston Garden.
    Instead, the 6-9 redhead was fishing around for his oversized sneakers and his green basketball shorts to go and work out with the struggling NBA Champions for the first time since he walked away from the club Nov. 10 because he wasn't having "any fun" anymore.
    There's a story behind it.
    I'm not in the Fun-and-Games Department here on The Post but I'm telling it because I happen to be involved in it, like a little more than an innocent bystander.
    It started with a telephone conversation between Red Auerbach and me a couple of weeks ago when Cowens let it be known that he was going to hang around that trotting track for the rest of the season and let the Celtics sit on what was left of the 28-year-old center's $280,000 salary minus the pay he drew for the eight games he played in before that strange "leave of absence."
    I told the Celtics' president (and the winningest coach in history) that. Cowens didn't belong in harness racing.
    Red called me back a couple of days later. He said he had Cowens in his office with him and asked me if I would have dinner with them if he brought Dave to New York.
    I said yes, I would do that, but I might be tempted to punch the big guy in the mouth for taking that stroll when the Celtics were going against the toughest Eastern Division competition in years--the Erving-McGinnis Philadelphia 76ers (four games ahead of them) and our own vastly-improved and beloved Knicks, tied with Boston for second place.
    Red relayed that to Cowens and the Kentucky boy said he thought he could take care of me. Red told the guy he couldn't lay a glove on me because I'm just a bare 5-8 and a 1/2 in my boots and also the coauthor of the Auerbach biography, "Winning the Hard Way."
    So last Monday night Red flew in from his Washington home, barely getting off the ground in the snow, and Mr. Cowens drove in from Philadelphia on the icy New Jersey Turnpike and we met at the House of Chan.
    Over the mixed appetizers, I asked Cowens what the hell he was going to do in the trotting arena while the team he helped to two NBA championships in six seasons was 18 and 18 and maybe in something of a struggle without him--what an unthinkable item for the greatest team in the league's history--and possibly just not good enough to make the playoffs without him.
    "I just don't feel like playing," the redhead said. "It isn't a mental problem. It's a physical problem. I wasn't getting enough out of my body."
    I said I wished I could buy the same kind of physical problem that resided in that incredible all-muscle body that had once instilled fear into towering centers like Kareem Abdul-Jabbar, Artis Gilmore and Bill Walton.
    Cowens said well, he wasn't helping the team enough.
     I said his stats--18 points and 15.3 rebounds, fractions below his career average of 19.1 and 15.5--didn't sound that bad to a bystander in the sport and reminded him that he was No. 2 in the all-star balloting so far.
    Red put in a word here, through the smoke of a huge black cigar Cowens had given him.
     "I never put any pressure on you, Dave, have I? Now I'm telling you to listen to this guy here. You belong in this game. You've always belonged in it. If you ever get any notion about coming back it oughta be before Feb. 13 in Milwaukee." (The All-Star game)
     "If they're voting me No. 2, then they don't want me in it," Cowens said, and I said...
     "Dave, did you say you didn't have a mental problem?"
     He didn't hit me. He just laughed that boyish laugh.
     So I kept talking...
     "I want to ask you a question, Dave. This has to be the single most exciting season in the whole history of professional basketball. A whole bunch of multi-millionaires with lifetime no-cut contracts arrived in Rolls-Royces from the ABA and turned the damn game around--and you're not in. I'm talking about Julius Erving and Artis Gilmore and David Thompson and Dan Issel. And you're gonna watch some guys sitting on sulkies behind trotting horses."
     Red didn't seem too happy with that kind of abrasive approach, but the real red-head (Auerbach's on the gray side now, let's face it) just put out another boyish smile and said he couldn't explain it.
     "You know, Paul," he said. "I'm not into the game that much. I just play."
     "You're not playing," I said. "Have you handled a basketball since this whacky thing started?"
     "No," he said.
     "Have you run?"
     "No."
     "Well," I said. "Something's crazy here. I've handled a basketball and I run three times a week--and I had a heart attack in '75--and Dave Cowens has a physical problem. What the hell is going on here?"
     Another shy, gentle laugh.
     So I went on--
     "Dave, you know, about any of the truly great athletes who ever took a walk while their teams were out there playing for the money. Guys like Joe DiMaggio, Pete Rose, Johnny Bench and Mickey Mantle, on those bad knees, that fellow named Russell whose shoes you stepped into, Bobby Orr...Want any more names?"
     "I don't follow sports that much, Paul. I don't know what to tell you."
     "Then keep listening to this guy," Auerbach said. "He's been up since four a.m. working on his newspaper and he's on his own time now. He oughta be in bed."
     The big kid kept listening. And Red dropped in a commercial item.
     He said that it wouldn't be fair to the Celtics if the man-in-the-middle went to work at a track twenty miles away that drew off cash customers from the Celtics own gate.
     Cowens said he hadn't thought about that.
     "You have to think about it, Dave," I said. "The Boston Garden's where you live. You lit the joint up when you came up from Florida."
     Dinner was over and Mr. Auerbach was blowing that awful cigar smoke again.
     "You know, Dave," he said. "We just came off a four and five road trip. The guys are knocking themselves out. We're not any cinch for the playoffs--and I'm still not putting any pressure on you, but I'll tell you something."
     "You kiss off that silly track and show up and we'll make the playoffs and we'll have just as good a chance as anybody else of winning it all. I'm not putting anybody down. It's one helluva league. Everybody got better and our guys are playing their guts out. Havlicek and Jo-Jo and Charlie (Scott), who broke an arm last night, and Rowe and Wicks. What kind of team have we got with you around again?"
     There was a faraway look in the big redhead's eyes now and five or six somehow useful breaks came when some strangers in the back room in the Chinese eatery came up and asked the big center in the checkered sports shirt for his autograph.
     The dinner was nearly over.
     Cowens still hadn't said a single word to indicate that anything either Red or I had said had moved him one way or another.
     We parted on the corner of Seventh Avenue and 52d Street, outside the joint in the wind-whipped cold.
     Cowens said he was driving back home. Red was going up to Boston later.
     And in the morning, Dave Cowens was going over to that trotting track in Foxboro.
     Something happened. No track.
     Around 3 o'clock in the afternoon Dave Cowens dropped into Red's office--into the cigar smoke--and said he'd like to work out with his old teammates today.
     There was no talk about money, no talk about back pay, no talk about any fancy new contract.
     Red just said he would put the guy back on the payroll as of that moment.
     And that was it.
     You might see the terrifying redhead banging heads in the league any night now. He feels like playing again.