A source with knowledge of the trade talks said Luol Deng has been included in proposals swapped between the teams, but Kobe Bryant has continually threatened to veto almost any deal in which Deng would be included. Bryant wants to be sure that the team he joins has enough talent remaining to compete for the NBA title.

The source said talks between the teams had stagnated, though by no means were they dead. And while the difficulties involved in the deal -- making the salaries match, and trying to trade players onto 15-man rosters now that the preseason roster flexibility has elapsed -- continued to be formidable, the Bulls remained determined to pursue every avenue toward acquiring Bryant from the Lakers.

As ESPN.com reported on Saturday, the Lakers have asked for Deng, Thomas, guard Ben Gordon and rookie Joakim Noah as the core parts of any trade for Bryant.

Contrary to most reports, the Bulls remain ready and willing to deal Deng, the source said. But if they're going to include Deng in a deal, they will not part with more than one of the other three, said the source.

Even then, it is not clear that any trade involving Deng would be acceptable to Bryant, who is wielding the power of the NBA's only no-trade clause by threatening to veto certain deals.

"It's not just the Bulls and Lakers who have to be happy with this deal. Kobe does, too, and that's a major factor," the source said.

The Bulls, according to ESPN.com's source, are willing to offer an alternative package of Gordon, Noah and Thomas.