By Alek Arend The NBA trade deadline is one of the most exciting days for basketball fans. But we often forget how stressful an experience it can be for the players. Doc Rivers understands what the experience is like. Rivers canceled the Sixers‘ practice on Thursday. Why? He wants his players to try and relax on what can often be a difficult day. “Doc Rivers canceled practice today. Said with everything going on, he canceled practice to let everyone just come in, relax and get some shots up. ‘Tomorrow, we’ll have shootaround with our team, for sure,’” wrote NBA insider Tim Bontemps. Doc Rivers…