http://msn.foxsports.com/nfl/story/5939908 The changes could include more testing and increasing the number of banned substances, according to a report on The New York Times' Web site on Wednesday. "We are in the process of re-evaluation, trying to determine if more is better, if it's the right time to add substances, to add more tests," Harold Henderson, the league's executive vice president for labor relations, told the paper. "It might make sense to do some tweaking." The NFL does approximately 10,000 tests for performance-enhancing drugs a year and there are about 2,000 players in the league. Players are randomly selected for testing and can be tested during the offseason. The NFL announced in June that it added amphetamines to the list of banned performance-enhancers starting this season. Amphetamines were previously listed as a "substance-abuse drug," but are now in the same category as steroids and other enhancers that carry much stronger penalties. This season will serve as a transition year, where a first positive test would bring a warning and put a player into the drug program. But in 2007, amphetamines will be tested for on a regular basis. A first positive test will result in a four-game suspension, the same penalty now levied for positive steroids tests. In addition to the amphetamines change, the penalty for a second positive test for performance-enhancing drugs was increased from six to eight games.