Mouth bleeding when catching ball?

Bella,our 1 yr old collie X staffie X whoknowswhat! loves catching balls more than anything in the world. So on one walk a day we try to do a fair bit of ball throwing for her. Trouble is she was destroying tennis balls at an alarming rate! In fact was almost costing me more in tennis balls than food LOL. So,on the advice of another dog owner we bought some really solid rubber type balls for her from PAH.
Now the last couple of times she has been playing ball her mouth has started bleeding At first I thought it was her claw(leaving blood on the ball),cause she has caught her and split it slightly and it is still healing abit. Then last night when she brought the ball back to me there was a big smear of blood on it,and when I checked I could see blood on the side of her mouth. I looked in her mouth,and couldn't see exactly where it was coming from. I then checked her mouth/lips/teeth/gums thoroughly when we got home and all looks fine. Her teeth are in excellent condition,and she doesnt seem in any pain at all. She can happily chomp away on a chicken wing/lamb rib etc with no problem,and I have only ever noticed the bleeding when playing ball.(we stopped playing last nigt when I saw the blood,but she would have happily carried on so it wasnt bothering her at all-just me LOL)
So....do you think the ball is just to heavy/hard for her when she jumps and catches it? or could it be a tooth problem?
She is booked into the vets for a check up next week,so will ask then but just wondered what others thought. Anyone ever had this problem?

Could she be nipping her tongue when she grabs at the ball, my girl does this quite often when she plays frisbee. Sometimes she is actually dripping with blood and other times you just see it smeared on the frisbee depending on how hard she caught her tongue in her teeth.

Could she be biting her tongue, Bruce our male does from time to time

yeah,could be. There was blood on her tongue,but I wasnt sure it was coming from there. It just scared me to see the blood on the ball,then dripping from her mouth ! It was quite tricky getting a good look though as I was in a muddy park,on my hands and knees,trying to restrain her when all she wanted to do was chase the ball, all whilst keeping half an eye on my 5 kids LOL I did have a good look later though as I said and all looked fine.
She is VERY enthusiastic about ball play....how can I stop her from biting her tongue if this is what it is ...couldnt not let her play ball...it really is her most favourite thing ever!

LOL Great minds think alike

You can't stop it happening and I really wouldn't worry too much about it. Tongues bleed a lot so it always looks worse than it is.

If its the tongue there is little you can do, Bruce just carries on we often throw a bloodied ball it doesn't bother them that much and it always looks worse than it is

on the same wave length

thanks both, you make a great double act!
well, she clearly isn't a bit bothered about it so I will stop worrying!