Sedlak had eight points (three goals, five assists) in 27 games with Philadelphia after being claimed on waivers from the Colorado Avalanche on Oct. 19.
The 29-year-old said he had been considering returning home for some time and informed the Flyers of his decision Friday.
"I just felt overall that me playing in NHL, it didn't bring me what I expected it to bring me and I would rather be home with my family," Sedlak said.
He said he expects to sign with Pardubice in the top Czech professional league.
"Kind of just last few weeks I was trying to figure it out, if I enjoy it, and if the hockey is still giving me kind of what I want from it," Sedlak said. "Because my family has sacrificed a lot for me being here. I haven't been home really for the last 12 years. And I think now, just the negatives kind of override the positives."
Sedlak said Flyers general manager Chuck Fletcher tried to convince Sedlak to stay, including in a meeting Saturday.
"I talked to [Fletcher] today again," Sedlak said. "He told me that I kind of have my spot here now and they liked me for what I do. ... He kind of wanted to change my mind, but then I kind of told him all my reasons and they were good enough to let me go, not to do anything else with me. So, I'm happy for that as well."
Sedlak played three seasons with the Columbus Blue Jackets (2016-19), then three seasons in the Kontinental Hockey League. He returned to the NHL when he signed a one-year contract with the Avalanche on June 13 but didn't have a point in three games when he was placed on waivers.
"When I came from Russia, I always played there a lot and I enjoyed playing a lot and kind of being the guy and stuff like that," Sedlak said. "I didn't expect to have that here. I kind of knew what I'm going to get, how many minutes, stuff like that. But I thought I'm going to feel better about it. When I signed with Colorado I kind of knew that I might have a chance to win, stuff like that. So that's of course part of the reason too. That's also why I left before, when I was in Columbus; I wanted to play. I'm getting to a certain age where it's not just about being in the NHL or playing in the NHL. It's also about playing, having fun playing, because I don't know how many good years I have left."
The Flyers (10-15-7), who lost 6-3 to the New York Rangers on Saturday, are seventh in the eight-team Metropolitan Division.
Forward Scott Laughton said he learned Sedlak would be leaving about an hour before Philadelphia held its morning skate.
"He was a great pro," Laughton said. "He's really good skater, on the PK helped us a ton, and face-offs. He came in when we were missing some key depth and did a really good job for us. He was a really good dude. I asked my buddy [Boone] Jenner about him, he played with him in Columbus, so I knew a little bit about him just from him. But yeah, good guy. At the end of the day, it's about being happy and comfortable and hope he finds that."
