Again plagued by injuries, this time a balky knee that required surgery on July 5, Sweeney got into just 74 games. He finished with a .260 average, seven home runs and 38 RBIs.
The Royals have not ruled out a return by Sweeney, the team captain and a dangerous hitter when healthy. His chronic back problems disappeared last season only to have the sore knee stop him.
When Sweeney came back from surgery in September, he batted .312 (19-for-61) in 17 games.
Riske was a big factor in the revived Royals' bullpen which went from last place in 2006 to sixth place in the American League ERA rankings this year.
Riske had a 2.45 ERA, four saves and a 1-4 record in 65 appearances primarily in a set-up role.
Signed last year as a free agent, Riske had his customarily rocky April with a 6.97 ERA in his first 10 games. Then he reeled off 18 straight scoreless innings and was tough the rest of the season.
He gave up runs in just 13 of his 65 outings and five of those came in April.
The Royals have interest in re-signing Riske, who is looking for a multiyear contract. He earned $2 million in 2007. Teams have exclusive negotiating rights to their players until Monday, Nov. 12.
The Royals announced they have declined their option to re-sign left-handed pitcher Odalis Perez for 2008. The option was reportedly worth $9 million with a $1.5 million buyout, half of which would be paid by his previous club, the Los Angeles Dodgers.
Perez and John Thomson, who made two starts last season, are the remaining Royals who can file for free agency.
Outfielder Reggie Sanders and catcher Jason LaRue filed on Monday.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.