OTTAWA — Mark Stone and the Ottawa Senators have more to worry about than snapping a four-game losing streak.

With the NHL trade deadline set for 3 p.m. ET on Monday, Ottawa could be sporting a much different look when it hits the ice Wednesday against the Washington Capitals. The Senators dropped a 5-3 decision Saturday afternoon to the Philadelphia Flyers, leaving many to wonder if captain Erik Karlsson has played his last game in the Canadian capital.

“This isn't an easy time for us,” said Stone. “I'm not going to shy away from that.

"You're kind of on pins and needles because you don't want to lose teammates and the talk around is that we are going to lose teammates. It's the nature of the business, we understand that, but it's difficult to keep that out of your mind.”

Karlsson, a two-time Norris Trophy winner, was once believed to be untouchable. But the smooth-skating defenceman has become one of the most talked about players who could be on the move Monday.

“He's been the face of the franchise for four, five years now so I think inside it's tough for us players to hear that type of stuff,” admitted Stone. “It's never easy.”

Saturday's contest was Ottawa's last before the deadline but its first since Derick Brassard was dealt to the Pittsburgh Penguins on Friday

"It's tough to say goodbye to some guys,” said Ottawa's Matt Duchene. “(Brassard) was a guy I've known for a little while and respect a lot so tough to say goodbye to him, but wish him the best.

"I know management has a plan so we'll see what this team looks like Monday.”

Philadelphia (33-19-10) earned its fifth straight win to move into a first-place tie with Pittsburgh atop the Metropolitan Division. Both teams have 76 points but the Penguins have three more wins (36) heading into their game Saturday night versus the Florida Panthers.

It's been an impressive rise for the Flyers, who stood 28th overall Dec. 3.

“I didn't think it was going to happen,” said captain Claude Giroux. “We're playing some good hockey right now.

"I'm not too sure what to say. Everyone bought in to what we're trying to do here and it's a lot of fun.”

Brandon Manning had a goal and two assists for the Flyers. Giroux, Ivan Provorov, Robert Hagg and Nolan Patrick also scored while Petr Mrazek made 25 saves.

Duchene, Mike Hoffman and Ryan Dzingel scored for Ottawa (21-30-10). Craig Anderson stopped 34 shots but suffered his 20th loss of the season.

Philadelphia broke open a 2-1 game with three third-period goals before Ottawa scored two late ones of no consequence.

The Flyers took a 3-1 lead on Giroux’s 22nd goal of the season. Manning sent Giroux in all alone and he made some great moves before beating Anderson in close.

“I saw I had a lot of time so I thought I’d have time to make an extra move,” said Giroux. “He’s a good goalie so I tried to fake him out.

"I don't think I've ever tried that move before, it just kind of happened.”

Patrick made it 4-1 at the 12-minute mark as he tipped in Manning’s shot.

Less than two minutes later, Manning made it 5-1 on a fortuitous bounce. Manning looked to shoot the puck down the boards and as Anderson went to play it, the puck took a weird bounce and went in the net.

Dzingel and Duchene added the late third-period goals for Ottawa.

The Senators outshot the Flyers 12-9 in the second and appeared to tie the game but had a goal called back.

Zack Smith scored at the 12-minute mark as he tapped in a Hoffman rebound. But the Flyers challenged the play believing it was offside and upon review won the challenge.

“That could have been a big turning point in the game,” said Flyers coach Dave Hakstol. “The fact that it was turned around was a real important part of the game for us.”

The Flyers opened the scoring just 28 seconds into the game as Provorov took a pass from Giroux in the slot and beat Anderson with a quick wrist shot.

Hagg made it 2-0 at the seven-minute mark for his second of the season. Hoffman cut the lead in half with a power-play goal, beating Mrazek on a one-timer.

NOTES: Ottawa defenceman Johnny Oduya was kept out of the lineup. Newly acquired defenceman Ian Cole was unable to get to Ottawa in time for the game . . . Philadelphia defenceman Shayne Gostisbehere played his 200th NHL career game.