Associated Press

NEW YORK — The NFL is going deeper into the wallets of players who get caught using steroids and other performance-enhancing drugs.

After four months of sometimes intense negotiations, the league and union announced Wednesday more extensive testing for performance-enhancing drugs and the addition of the blood-boosting substance EPO to its list of banned substances.

“It is important that the NFL and its players continue to be leaders on the issue of illegal and dangerous performance-enhancing drugs in sports,” NFL commissioner Roger Goodell said. “These latest improvements will help ensure that we continue to have a strong and effective program. As we have done in the past, we will review and modify the policy on an ongoing basis.”

The union also agreed that players suspended after testing positive will, for the first time, forfeit a portion of their signing bonuses in addition to the salary they will lose during their time away.

That is significant because the signing bonuses often are the only guaranteed portion of a player’s salary and can be larger than salaries, which sometimes are kept artificially low to keep the team under the salary cap.

In addition to the new test for EPO, the agreement includes an increase from seven to 10 of the number of players on each team randomly tested each week during the season.

The new policy will make the NFL the only North American sports league to regularly test for EPO. Urine will be tested, not blood, for EPO.