John "Hot Rod" Williams was close to signing an offer sheet with the Miami Heat yesterday, but his agent and team officials denied a report of a seven-year, $28 million deal.

The 6-foot-11 Williams, a Cleveland Cavalier since he entered the NBA four years ago, is one of the most attractive restricted free agents available. The Cavs would have 15 days to match any offer; he rejected their five-year, $13 million extension offer two months ago.

A report in the National said the Heat would offer Williams the $4 million-a-year package, making him the NBA's second-highest paid player behind Houston's Akeem Olajuwon.

"What's been discussed isn't that much," Heat managing partner Lewis Schaffel said. "What they are asking for isn't that much." . . .

First-round draft choice Elden Campbell, 6-11 from Clemson, signed with the Los Angeles Lakers after checking out Italy. No terms were announced except that it is for more than one season. . . . Forward David Greenwood signed with San Antonio. An 11-year NBA veteran, he became a free agent after a year as a Detroit reserve and opted to rejoin the Spurs, with whom he spent 3 1/2 seasons, 1985-89.