Chicago defenceman Brent Sopel is the subject of trade rumours. (Jonathan Daniel/Getty Images)

The Chicago Blackhawks have a real problem on their hands, and a deal with the Toronto Maple Leafs could be on the horizon,Hockey Night in Canada contributor Pierre LeBrun said on Saturday's Hotstove segment.

The Blackhawks have agreed to contract extensions with three of their young stars, he said, but they can't formally announce the deals with Patrick Kane, Jonathan Toews and Duncan Keith until they shed some salary off their current roster.

Although the new contracts wouldn't take effect until next season, the Blackhawks are subject to the NHL's "tagging" rule, which prohibits a team from having more money committed to the following season than the current season's salary cap.

This year's cap is about $56 million US, meaning Chicago wouldn't be allowed to have the projected $61 million US committed to next year's payroll after these three deals were completed.

To make room for the new contracts, the Blackhawks are reportedly shopping defenceman Brent Sopel and his $2.3 million salary, LeBrun revealed.

The struggling Toronto Maple Leafs are interested, he said.

Player agent Ian Pulver said the tagging rule highlights a flaw in the current salary cap system.

"It doesn't make sense," he told HNIC.

"If the Chicago Blackhawks want to sign three players for next year, they shouldn't have to give up a player on their current roster. There's something wrong in that mix that needs to be addressed."

Toronto GM Brian Burke is hoping to capitalize on the Blackhawks' cap woes.

He's starting to feel pressure to pick up a draft choice to replace the three picks he traded away to Boston in the Phil Kessel deal, LeBrun said.

"Burke is feverishly working on trying to get something done," he said.

"The theme of his pitch is 'I can take on some of your cap issues, and give me a draft pick in return.' I think he's talking to the Chicago Blackhawks, and Brent Sopel is the guy he's willing to take."

CBC cameras showed Blackhawks assistant GM Kevin Cheveldayoff in the media box at the Air Canada Centre for Saturday's contest between the Leafs and the Washington Capitals.

Players are struggling to deal with the fact that future contract extensions are having an impact on this year's rosters, Pulver said.

"Players are changing their attitudes about what's good for them, versus what's good for the team."

As general managers and players look for ways to adjust in the salary cap era, it appears the NHL will continue to look overseas for more sources of revenue.

Six teams — Minnesota, Carolina, Boston, Columbus, Phoenix and San Jose — are on the list to play regular-season games in Europe next year, LeBrun said.

Pulver hopes it means the NHL is also willing to commit to sending its players to the 2014 Sochi Olympics in Russia.

There are also serious money concerns in many of the smaller U.S. markets, Pulver revealed.

Many of the teams who normally qualify for payments from the NHL's revenue-sharing program aren't getting them.

"It's a big issue," he said.