Damon, the speedy Kansas City outfielder coveted by many big-market teams, was acquired by the A's on Monday in a surprising three-team trade involving nine players.
Catcher A.J. Hinch and reliever Cory Lidle were the only other major league players in the deal.
Though Damon, one of the most sought-after players on the trade market, will be eligible for free agency after next season and will demand the kind of money the small-market Royals knew they could never pay, the AL West champion A's felt the risk of losing Damon next winter was outweighed by his talents.
"That's part of the risk you take when you go into something like this to make us much better," Oakland GM Billy Beane said. "This is a dimension that this team hasn't had for the last two years. We haven't had this type of player probably since Rickey (Henderson) was in his prime."
The deal gives the Devil Rays another powerful bat while continuing their youth movement, and it gives the Royals badly needed bullpen help.
But most significantly, it gives a new dimension to the Athletics, who stole just 40 bases last year, often played terrible defense and relied heavily on the long ball.
"It means we've got to get a steal sign now," Beane said.
Damon's agent, Scott Boras, said the leadoff hitter will test the market before signing a contract extension anywhere.
"The timetable was running out, and that's what dictated this," a somber Kansas City GM Allard Baird said. "If we had felt for one minute that we could sign Johnny to a long-term deal, then obviously we would not have made this deal."
The A's still must sign him for the current season either through arbitration or negotiation, but Beane was confident a deal would be completed soon.
Damon hit .327 with 16 homers and 88 RBIs last season for the Royals, the fifth straight year in which his offensive numbers improved. He had career highs in hits (214), runs (136), doubles (42), RBIs, batting average, on-base percentage and slugging percentage.
He led the AL with 46 stolen bases and 136 runs scored. Beane also noted that Damon had a higher slugging percentage (.495) than Grieve (.487).
Beane admitted the A's wanted to improve in the wake of Alex Rodiguez's $252 million signing with AL West rival Texas.
Several teams wanted Damon, including the Los Angeles Dodgers, the New York Mets and Oakland's cross-bay neighbors, the San Francisco Giants. But by sacrificing part of their impressive stockpile of young talent, the A's got him even if it's only for a year.
"Johnny Damon brings a lot of things that this club was lacking," Beane said. "Plus, how many times are you going to find a guy with his kind of speed and his kind of defensive abilities who also has a chance to hit 20 homers a year?"
Grieve hit .279 with 27 homers and 104 RBIs last season, but the A's had been looking to deal him this offseason after he struck out a career-high 130 times and grounded into a major league-leading 32 double plays.
He signed a four-year, $13 million deal last March, but just two seasons after bursting onto the scene for Oakland, he had become a spare part on a team with AL MVP Jason Giambi, Terrence Long, Adam Piatt and John Jaha.
"We could not pass the opportunity to get a young bat like Ben's," said Devil Rays GM Chuck LaMar, who also admitted that Grieve's secure contract status was attractive. "In our opinion, the sky's the limit for what he can accomplish at the plate."
Hernandez was 4-7 with a 3.19 ERA and 32 saves last season. The 36-year-old right-hander has been among the majors' top relievers for several seasons.
"He's arguably been our most valuable player since the franchise started," LaMar said. "We've been very resilient in coming up with pitching, and we're going to have to do it again."
The Royals also acquired Hinch, 26, minor league infielder Angel Berroa and cash from the A's. Baird called Berroa a key to the deal.
"He is a legitimate shortstop, tremendous upside," Baird said.
Regarded as a top prospect early in his career, Hinch played only six games for Oakland last season. Berroa hit .277 with 10 home runs and 63 RBIs for Class A Visalia.
The Athletics got Lidle, 28, from Tampa Bay. He was 4-6 with a 5.03 ERA in 31 games, and his performance in a 4-0 shutout of Oakland in September put his name on the A's list.
Oakland also acquired minor league infielder Mark Ellis and a player to be named from Kansas City. Ellis hit a combined .302 with 26 stolen bases in Class A and Double-A.
Tampa Bay got a player to be named or cash from the Athletics.
Oakland designatepitcher Ariel Prieto for assignment. He was 1-2 with a 5.12 ERA for the A's.
©2001 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed