Just days after Boston University released a massive new study into degenerative brain disease and football players, it's been revealed that the National Institutes of Health (NIH) is set to end its partnership with the NFL. This leaves millions of the pledged funding left unused and unpaid, according to ESPN.

The NFL announced in 2012 it was providing the NIH with $30 million of funding towards medical research into brain injuries and concussion. However, this partnership was certainly not the easiest of relationships, to say the very least. Their agreement is now set to expire in a month's time, on August 31, but there's still $16 million of the funding left hanging in the balance.

“The NFL's agreement with [the funding arm of the NIH] ends August 31, 2017, and there are no current research plans for the funds remaining from the original $30 million NFL commitment," the NIH told ESPN in a statement. "NIH is currently funding concussion research directly.”

"If [the] NFL wishes to continue to support research at NIH, a simple donation to the NIH Gift Fund to support research on sports medicine would be favorably viewed, as long as the terms provided broad latitude in decisions about specific research programs."

Nevertheless, the NFL still say they intend to stick to their commitment.

“We are currently engaged in constructive discussions with the [Foundation for the National Institutes of Health] regarding potential new research projects and the remaining funds of our $30 million commitment,” the NFL said in a statement obtained by The Washington Post.

Although hailed as a major step forward when first announced, the partnership between the NIH and the NFL has had its fair share of trouble from the get-go. A report from May 2016, issued by Democrats from the House Committee on Energy and Commerce, found that the NFL “improperly attempted to influence the grant selection process at NIH.” In sum, the NFL was accused of attempting to use its “unrestricted gift” as leverage to steer funding away from one of its critics, a Boston University team led by researcher Robert Stern.

Last week, on July 25, Boston University released a widely talked about study looking at the brains of deceased football players and chronic traumatic encephalopathy (CTE), a degenerative brain disease associated with repeated physical trauma to the head. Out of 202 deceased American football players, 177 were diagnosed with CTE. Out of the 111 NFL players, 110 showed signs of CTE.

Following this study, the NFL claimed they are "committed to supporting scientific research into CTE and advancing progress in the prevention and treatment of head injuries."