A month ago, it seemed to be an inevitability. Rockets center Omer Asik was unhappy with his role behind newly signed star Dwight Howard, and had requested a trade.

Now, league sources have told Sporting News that it will be increasingly difficult for Houston to move Asik, who has been out since the beginning of December with a deep thigh bruise. Asik could return soon, and when he does, it is likely that he will finish out the year with Houston. The same, too, could be said of point guard Jeremy Lin.

That’s because of the structure of the contracts the two players signed back in the summer of 2012, when each was a restricted free agent. There is a loophole in NBA rules that allowed Lin and Asik to sign three-year, $25 million contracts, in which they are paid $5 million for the first two years and $15 million for the third year.

When it comes to how the players are calculated against the salary cap, the $25 million is averaged over the three years—$8.33 million per year—but in real dollars, Asik and Lin will receive $15 million each next year.

Had either player been dealt early this season, the $15 million payment would have been somewhat offset by the fact that each gets only $5 million this year. But the more time passes, the more that the offset salary dries up, and the harder it is to trade either player.