Tim Duncan is not expected to opt out of the final year of his contract, and the Spurs don’t plan to offer him an extension before the collective bargaining agreement expires Thursday, according to a source familiar with talks between the team and the franchise icon.

As such, Duncan will play out the final year of his existing deal, during which he is scheduled to earn $21.2 million, and remains on track to become a free agent after the 2011-12 campaign.

Duncan faces a Thursday deadline to exercise a early-termination option.