Sieloff was traded to the Lightning from Anaheim for Chris Mueller on Monday.
Sieloff was demoted to AHL Belleville on Wednesday.
Sieloff was called up from AHL Belleville on Tuesday.
The Senators waived Sieloff on Friday Bruce Garrioch of the Ottawa Sun reports.
Sieloff signed a one-year, two-way contract with Ottawa on Tuesday.
Sieloff was acquired from Calgary on Monday by the Senators in exchange for Alex Chiasson.
The Flames have assigned Sieloff to AHL Stockton.
Sieloff scored the go-ahead goal in his NHL debut Saturday against the Wild.
Sieloff was recalled from AHL Adirondack on Friday
Patrick Sieloff is looking forward to making up for lost time now that he's recovered from a staph infection.
Sieloff only played in two AHL games in 2013-14, but he will join the Flames' other prospects for their development camp. "It's so great to be here," he said. "I've been feeling good all summer. There hasn't been any hiccups or anything. For me, this is camp ... it's staying on the ice and staying healthy. I can build confidence off of those two things." He'll need some seasoning in the minors before he'll be ready to compete for a spot with the Flames.