Updated

The Ottawa Senators' road to the postseason will be a bumpy one after they learned last week they will be without with reigning Norris Trophy-winning defenseman Erik Karlsson for the remainder of the season with a torn Achilles tendon.

While the Sens won't be able to find someone who can replace everything that Karlsson brought to the table, there are a number of defensemen potentially available who the Sens can target as the trade deadline approaches and more teams begin to drop out of playoff contention.

Here is a look at three blue-liners who could be on the Sens' radar:

KEITH YANDLE - PHOENIX COYOTES (2-8-10 in 16 games this season)

It's not often one of the league's most dynamic offensive defensemen, who is just 26 and has plenty of upside, would be made available, but in Yandle's case there have been some rumblings that perhaps the Coyotes would look to shop the two-time NHL All-Star. Yandle's offensive ability isn't quite at Karlsson's level, but he would certainly help make up a lot of the offense that the Sens are now without from the back end.

A great puck-mover who eats up plenty of ice time, particularly on the man- advantage, he seems to have lost the top defenseman billing in the desert to up-and-comer Oliver Ekman-Larsson, which would explain perhaps why his name has been tossed around in potential trade talks.

Yandle is signed through the 2015-16 season with the Coyotes at an annual average salary of $5.25 million, but he does not have a no-trade clause. His name also has been linked lately to the Boston Bruins and Philadelphia Flyers.

JAY BOUWMEESTER - CALGARY FLAMES (3-4-7 in 14 games this season)

Bouwmeester is another blue-liner who has seen his name thrown around the rumor mill, although, unlike Yandle, it makes a bit more sense.

It's no secret Bouwmeester has not lived up to the expectations the Flames had for him when they acquired him from the Florida Panthers in 2009, and if Calgary ever finally opted to go down the rebuild path, then Bouwmeester is likely going to be among the first to be jettisoned.

Bouwmeester can sometimes be a liability in his own end and his offensive game isn't quite at the same level as before he joined Calgary, but he does log a ton of minutes and would be able to step right into a top-two role.

Bouwmeester has a no-movement clause and a cap hit of $6.68 million this season and next, but would probably cost the Senators fewer assets to acquire compared to the aforementioned Yandle.

LUBOMIR VISNOVSKY - NEW YORK ISLANDERS (0-4-4 in 6 games this season)

If the Senators are seeking a more temporary and financially viable option, then Visnovsky fits that bill.

The 36-year-old journeyman defenseman is only two years removed from a career season in which he notched 18 goals and 68 points with the Ducks and is still regarded as one of the league's most dependable offensive defensemen and can still log plenty of minutes as he's shown in the early part of this season.

Visnovsky carries a $5.6 million cap hit this season although his take-home salary is significantly less than that. He's also an unrestricted free agent at the end of the season, so there are no long-term ramifications to worry about in case things don't pan out the way the Sens hope.

The asking price for Visnovsky should be relatively reasonable and could fall even more as the Islanders start to slip out of the playoff race.