Michael Sam has admitted that he needs to up his game in order to secure a place in the St Louis Rams' 53-man roster.
The defensive end, who is the first openly-gay player in the NFL, was selected in the seventh round of the Draft last month.
The 24-year-old told USA Today: "I've got to step my game up to compete with this defensive line. I thought our defensive line at Mizzou was pretty tough. This is a whole new level. I've got to up my game."
Sam made 123 tackles, 21 sacks and six forced fumbles during his college career with Missouri.