Richard Berthelsen has been a lawyer at the National Football League Players Association for nearly 37 years, but his most demanding year has been the past one. Berthelsen, the union’s general counsel, also became its interim leader after the sudden death of its longtime executive director in August. Since then he’s filed grievances for players in several high-profile suspensions and testified in a class action brought by retired players. Plus, he’s been meeting with teams to talk about the future of the league’s collective bargaining agreement, which the owners opted to let expire ahead of schedule.

Berthelsen acknowledges the pressure. The 64-year-old lawyer says that “the stress level has gone up” since he took over the top job. The largest change hasn’t been the workload, he explains, but the increased responsibility.