From inside the article:
“There’s a sense around the league that the Dallas Cowboys aren’t done making a push for Thomas, who’d fill a major need on their defense. Two sources said the trade discussions between Seattle and Dallas have centered around the Cowboys’ second-round pick (No. 50 overall) but that no deal will be done until the Cowboys figure out whether they can sign Thomas long term. Thomas has one year and $8.5 million left on his contract, which would make him a great deal for the 2018 Cowboys. But dealing a second-rounder for a one-year rental wouldn’t make a lot of sense. If a deal gets struck, expect news of a Thomas contract extension with Dallas to follow.”