Los Angeles (CNN) -- The recent recovery of one of his stolen trophies and several scrapbook items at a Los Angeles park left tennis legend Pete Sampras "a little more optimistic" that the rest of his coveted memorabilia will soon be found, his agent said Monday.
Thieves last month broke into a public storage facility that the 14-time Grand Slam titleholder was renting as he and his family moved from their Thousand Oaks, California, estate to nearby Brentwood. Afterward, Sampras learned that 51 of his 64 championship trophies -- including one marking his first Australian Open cup -- were among the coveted items stolen.
His agent, Grant Chen, said authorities contacted Sampras after one of those trophies and several other items were found late last week at the Griffith Park Recreation Center in Los Angeles. The park, one of the nation's largest situated south of Burbank and west of Glendale, is about 20 miles east of the West Los Angeles storage site from which the trophies were stolen.
Los Angeles Department of Parks and Recreation spokeswoman Andrea Epstein declined to comment on the find, referring inquiries to Los Angeles Police. That office would not talk about the investigation.
Sampras and his wife Bridgette Wilson-Sampras, an actress, recently listed their Thousand Oaks property, which is on the grounds of the Sherwood Country Club, for sale at $25 million.
"The moving company we hired is very well trusted, and we've used them before," said Chen, who helped the Sampras family -- including sons Christian, 8, and Ryan, 5 -- pack and move. "Only a few people knew the contents of the 50 to 60 tightly sealed boxes that we stored."
Sampras can account for all but one of the 14 Grand Slam trophies -- given for his wins at the Australian Open, Wimbledon and the U.S. Open. Most of them Sampras brought personally to his new home, while he loaned his 1993 Wimbledon men's singles trophy, 1997 Australian men's singles title and one Davis Cup trophy to the Nike headquarters in Oregon.
The only one stolen was his 1994 Australian Grand Slam title, said Chen.
Steven Glick, a spokesman for Public Storage in West Los Angeles, told CNN that his company is "fully cooperating" with investigators, but he declined to elaborate.
Sampras, 39, was awarded five season-ending Association of Tennis Professional World Tour trophies and six trophies for finishing No. 1 in the world from 1993 to 1998. Those valuables, as well as seven ESPY awards, two Davis Cup medallions and an Olympic ring, were among those stolen from two rental units, Chen said.
In addition to his titles, Chen said thieves took framed photographs of Sampras with Presidents George H.W. Bush and Bill Clinton, as well as some personal letters written by Bush. Other stolen items included a piano bench signed by singer Elton John and a signed guitar from Carlos Santana.
Sampras, who grew up in Southern California, defeated Andre Agassi at the 2002 U.S. Open before retiring the following year with the most Grand Slam wins in tennis history. Roger Federer later surpassed his record with 16 major titles.
"Sampras pleaded with the public as a last resort, (hoping) that someone will offer a tip or come forward," said Chen. "Those stolen items represent memories of a lifetime, and Pete wants nothing more than to share those memories with his sons."