son hurt

Last night my son had a football game. He was having such an awesome game too! His team was losing terribly, but every tackle was made by him!  He was put in the game because another player was injured and so he just went in and played his heart out. He had no clue what he was doing at first; soon he was comfortable and looked like he had been playing that position from the start.  He usually starts offensive line and special teams.  He was thrown in on defense and did so well. Until he made a tackle and then couldn't stand up. His right knee "popped" he said and then it was over. He cannot put weight on his right leg at all.  My ex husband is going to take him to the doctor today. At least he said he would.  I am worried. I couldn't see the person that was hurt to tell who it was; but I knew in my heart that it was him.  He got up and walked off the field and seemed ok. When the coaches let go of him on the sidelines, his leg just buckled and he went down.  Thankfully I have walk aids at home.  He is using my walker to get around for the moment. He will get some crutches from his dad today...but he has some independence using my walker.  I was helping him get around all night until my husband said to get my walker out for him.  I guess I just wasn't thinking.  I am worried and trying not to get too stressed about it.   I don't need to have problems walking along with him.  He is so disappointed because he wanted to play in the last game next week.  Now he is worried about basketball too...hope it is just a sprain!