Sean Landeta never thought he would have a day like yesterday. He realized that someday his career as a National Football League punter would end. He just had no idea that now, at the age of 31, he would be fired by the New York Giants. And so he relaxed yesterday at his handsome, new white brick home in Lutherville. He wore shorts and a T-shirt and over-the-calf athletic socks. In his hand he held a portable telephone that wouldn't stay silent for more than three minutes at a time as friends called to ask how he was doing. "If I was punting bad, I could understand it," said Landeta, who punted and kicked at Towson State before becoming the best punter in pro football. "I'll bet I'm the only punter with a 42-yard average who ever got fired." Tuesday at Giants Stadium, first-year coach Dan Reeves called Landeta to his office. Sean knew Reeves wasn't pleased with his punting in the loss at Dallas last Sunday. The coach had said so in front of the squad Monday, which Landeta thought was a little unfair. And then Reeves dropped the bomb into the lap of the five-time NFL All-Star. "Reeves was very nice about it," Sean recalled as his wife, Pam, puttered in their huge kitchen. "He said he likes me and he appreciates that I'm a competitor. He thanked me for what I've done for the Giants. "He even said he'd help me to catch on somewhere else. Almost too polite. He just wanted to have his own man, whatever that means." What it means is that when Reeves calls for a punt against the Washington Redskins Sunday at Giants Stadium, the man who boots it will be Mike Horan, a nine-year veteran who played seven years under Reeves at Denver. Dan's own man. "I don't know what the Giants gain by this," says Tony Agnone, Landeta's Baltimore-based agent. "Moran is almost 35 years old; Sean is 31. And Sean Landeta has a chance to become the first punter ever to go to the Hall of Fame." Landeta didn't feel much like a Hall of Famer yesterday as he waited for his name to clear NFL waivers. "In football," Sean said earnestly, "when you get fired you don't get paid. The money is not guaranteed. It's a good thing this house is paid for in full." Pam, Sean's wife of two years, was handling things magnificently. "I think Sean will be punting for another team very soon," Pam said confidently. "Whatever he does and wherever he goes I'm 100 percent behind him. We haven't started a family yet so I can go anywhere. I'd even be happy in Green Bay." Rejection must be especially tough for Landeta, who is imbued with supreme confidence. The first time I met him was at a Towson State celebrity golf tournament at Hunt Valley. Sean was a sophomore on the Tigers football team but I had no idea who he was when he approached and began telling me of his punting and kicking talent. "I was working out this morning with Tony Linhart and David Lee," Sean said, "and I outkicked them both, consistently." Later I told Towson coach Phil Albert that the young man had boasted he could outkick the Baltimore Colts' best. Albert laughed. "That's Sean Landeta," Albert said. "He probably can outkick the guys the Colts have. Sean's a great kicker, but he's . . . well, he's different." Landeta's former teammates at Towson recall two-a-day practices when they wondered if they would survive the 102-degree heat and the August humidity. And Landeta, who did nothing but punt on the side while the rest of the team scrimmaged, would stick his head in the huddle and say: "You guys are killing yourselves and I'm the only one out here who's going to the NFL." He didn't go to the NFL right away. He went first to the United States Football League's Philadelphia Stars, who later became the Baltimore Stars. When the USFL folded, New York Giants general manager George Young, an ex-Baltimorean, brought Landeta to the NFL. "If I never play another game," Sean said yesterday, "I've done everything a punter could do. Super Bowls. Pro Bowls. Championship teams. But I know I can still punt. I want to go somewhere and play another three, four or five years." Now, halfway through '93, he looks forward to joining a new team. The way his telephone was ringing yesterday, it was obvious people are interested. Landeta was to make $3 million over the next four years, which made him the NFL's highest paid punter. Cutting him before the ninth game, the Giants don't have to pay him anything. "Somebody else will pay it," Agnone said. "Sean could lose a few bucks but they won't have to hold a benefit for him."