The Panthers play the New Jersey Devils at Prudential Center on Monday (7 p.m. ET; MSG+, FS-F, NHL.TV).
"It's a huge blow for us, offensively," Florida coach Bob Boughner said. "Our 5-on-5 game has been pretty good, but we've been struggling to score goals and [Dadonov] is an offensive player. So it won't help our cause, but it gives an opportunity for guys like [Denis Malgin] to step in and get a chance to play on the top line."
Malgin was recalled from Springfield of the American Hockey League on Monday.
Dadonov ranks fourth on the Panthers with 18 points (seven goals, 11 assists) in 22 games playing mostly with center Aleksander Barkov and left wing Jonathan Huberdeau. He replaced Jaromir Jagr on the top line after the Panthers opted not to re-sign Jagr, who signed a one-year, $1 million contract with the Calgary Flames on Oct. 4.
Dadonov, 28, signed a three-year, $12 million contract June 30. He was selected in the third round (No. 71) of the 2007 NHL Draft by the Panthers and played 55 games from 2009-12 and spent the past four seasons in the Kontinental Hockey League.
"It's a tough situation, but [Malgin] has been good in Springfield," Boughner said. "He's an offensive guy so hopefully he can take advantage of that and give our power play a different look. We'll have to switch around guys on the power play because [Dadonov] was a big part of that (six power-play points)."
Malgin, a fourth-round pick (No. 102) in the 2015 NHL Draft, has 14 points (four goals, 10 assists) in 13 games for Springfield.