Roberts, an unrestricted free agent July 1, was trying to decide if he should waive his no-trade clause for a move to the Penguins, a source told The Canadian Press.
Roberts, 40, could still turn down the Pittsburgh deal and ask the Panthers to re-visit talks with other clubs, notably the two teams he really wants to move to: Ottawa and Toronto.
Fredrik Modin, meanwhile, isn't going anywhere. The Swedish winger officially signed a US$9.75-million, three-year contract extension with the Columbus Blue Jackets.
"He's a character person, he's a leader, he's a winner," Jackets GM Doug MacLean told The Canadian Press. "He wanted to be here and be part of the program and we really wanted him. And when you trade Marc Denis for a player like Freddie and (Fredrik) Norrena you want to keep those assets."
Norrena signed a two-year extension earlier this month. He was acquired from Tampa Bay along with Modin last July in exchange for Denis.
MacLean also put Bryan Berard on waivers Monday. The defenceman was one of nine players put on waivers around the league on the eve of Tuesday's 3 p.m. ET trading deadline.
Berard has been on the trade block for a month. He's an unrestricted free agent July 1 but carries a $2.5-million salary this season, which could scare away clubs too close to the $44-million salary cap.
Other players put on 24-hour waivers Monday included: Marc Chouinard, Vancouver; Aaron Downey, Montreal; Petr Cajanek, St. Louis; Niko Kapanen and Denis Hamel, Atlanta; Michael Leighton, Philadelphia; Jason Krog, N.Y. Rangers and Brian Boucher, Chicago.
Chouinard, who has been a disappointment this season, has another year on his deal next season at $1.1 million. Canucks GM Dave Nonis is likely trying to create more cap room for himself by having another team hopefully pluck Chouinard off waivers.
With Alex Kovalev returning from a sore elbow in Montreal, the Canadiens needed to open a roster spot so Downey was put on waivers. The tough guy winger has played in only 21 games this season and was a healthy scratch for the last six games. He has one goal, no assists and 48 penalty minutes this season. He's earning $475,000 this season and will be an unrestricted free agent July 1.
Cajanek could be tempting for some playoff-bound clubs looking for scoring. He's making $1.7 million this season and $2 million next season.
Kapanen and Hamel were waived after the Thrashers added Keith Tkachuk and Alexei Zhitnik to the lineup over the weekend. Kapanen is earning $800,000 this season and $900,000 next year.
Meanwhile, the rumour mill continued to churn Monday. One name that surfaced yet again is Jason Blake, the leading scorer of the New York Islanders. Unable to come to terms on a new contract, the Isles could be willing to move the pending unrestricted free agent despite being in a playoff race. Two GMs, who requested anonymity, told CP that Blake was available. The 33-year-old winger is attracting attention from several Western Conference teams.
And what about Todd Bertuzzi? Another pending unrestricted free agent, Bertuzzi hasn't played since October and still isn't ready to return after recovering from back surgery. But Panthers GM Jacques Martin told CP over the weekend that teams were still calling about him.
Other players expected to move include winger Kyle Calder in Philadelphia and defenceman Brent Sopel in Los Angeles - both unrestricted free agents.