I imagine Welker is upset because if he catches just one more pass, there's a very good chance they win. He's thinking he cost his team a SB win. A player feeling bad about a loss and being comforted is not whining. Admittedly, I haven't seen any of these videos or really kept up with what the players are saying, but I think the loser of a SB, no matter the team, is entitled to feel bad about it. Whinning is 'But Ma, Billy cheated me! He didn't play fair." I haven't heard any of this. If Welker were to twitter something like "If only I caught that pass", that's not whining, that's lamenting.