He could now face yet another surgery on the injured shoulder.
"It looks like Peter is out for the season," Senators GM Bryan Murray told the Sun. "He hasn't had surgery, but it looks like thatís what is happening here."
Murray acquired center Kyle Turris from the Phoenix Coyotes to fill the hole left by Regin on the second line.
The Senators are expected to add more via the trade route and could obtain more help up front to ensure they remain in a position for a playoff spot.
In 10 games this season, Regin collected two goals and two assists for four points.
More Trade Deadline Info
List of Trades
| No-Trade/No-Movement Clauses
| Top 25 Available Players
| Team-by-Team Cap Info