Tony Romo’s tenure as a Dallas Cowboy will come to an end Thursday, sources within the organization confirmed to WFAA's Rebecca Lopez.

Thursday marks the start of the NFL’s new league year, and also the beginning of free agency. The Cowboys had been searching for a trade partner for the organization's all-time leading passer, but were apparently unsuccessful.

It isn't clear whether Romo will be released outright or designated as a post June 1 cut. Releasing Romo would give the Cowboys $5.1 million in cap relief for the 2017 free agency period. Designating him as a post-June 1 cut would cost the Cowboys nearly $25 million, but that money could be split over 2017 and 2018.

Photos: Tony Romo's Cowboys career

Romo, who will be 37 at the start of next football season, has a $14 million base salary for 2017.

Romo has spent 14 seasons with Dallas, but was supplanted as the team’s starter this season by rookie standout Dak Prescott. He has played just five games over the past two seasons due to back and collarbone injuries.

The veteran QB’s top suitors are believed to be the Denver Broncos, Houston Texans and San Francisco 49ers. CBS Sports' Jason La Canfora also added the Los Angeles Rams to that list in a report last week.