"He has been working so hard this past week! Such a beautiful person inside and out!" she added about the transgender advocate, who was born Chastity Bono to entertainers Sonny and Cher but underwent a sex change in 2009 and legally became a man last year.
Schwimmer's feelings about Bono are mutual according to the 42-year-old, who will be the first transgender person to compete on the ABC reality ballroom dancing competition.
"[Lacey] really thought it was great that I was doing it and wanted to know how I was feeling about it -- if I was nervous and how it was going," Bono said during a Wednesday appearance on Ryan Seacrest's On Air with Ryan Seacrest radio show.
"We met last week and just kind of instantly hit it off... she's just great. I was so nervous going into it about who my partner was going to be -- you have no idea until you meet them -- and I was really relieved that it was Lacey... I just dig her... she has a great attitude for teaching me."
According to Bono, Dancing with the Stars producers originally wanted him to compete on last spring's twelfth edition.
However, the season conflicted with his promotional commitments to Becoming Chaz, a documentary that chronicled his transition from female to male, and Transition: The Story of How I Became a Man, an autobiography he released earlier this year.
"Originally, they had contacted me right after my book and film came out and I was doing all the press for it last season, so I didn't do it. So when I got finished with everything, we checked back in with them about doing it this season," he told Seacrest.
Dancing with the Stars' thirteenth season will premiere Monday, September 19 at 8PM ET/PT with a two-hour broadcast.
All 12 celebrities will perform a Viennese waltz or cha cha routine with their professional partner during the premiere, and the couple with the lowest combination of the judges' scores and home viewer votes will be eliminated on the following night's results show.