FRISCO, Texas – If there was doubt about Jason Witten's long-term future with the Cowboys, he erased it on Tuesday morning.

Witten signed a four-year contract extension to remain with the Cowboys through 2021, the club confirmed. The deal maxes out at a possible $29.6 million, according to reports.

The extension won't change Witten's $7.4 million salary or his $12.6 million salary cap charge for 2017, which were part of his pre-existing deal. However, it does grant the Cowboys the freedom to restructure the contract if they so choose, freeing up roughly $4 million in the process.

There had been speculation that Witten's playing career might be headed toward a close back in January, immediately following the Cowboys' playoff loss to Green Bay. Following this extension, though, that hardly seems to be the case.

The 2017 season will be Witten's 15th with the Cowboys, tying a franchise record set by Ed "Too Tall" Jones, Bill Bates and Mark Tuinei. If Witten plays the entirety of his contract – or even just a couple more seasons – he could set a new standard as the longest-tenured Cowboy in franchise history.