According to Josh Thomson on facebook:
"Cain is wrestling every day with this years NCAA Div 1 national champ from MO. who is about 280lbs and let me tell you that Cain coming off a knee surgery 4wks ago is getting takedowns just fine as well as not losing any. Cain is a better wrestler/striker/MMA fighter than Brock but like you said, Brock is bigger with a huge punch. That is the only chance I give Brock though is a punchers chance cuz I don’t see him holding Cain down "IF" he can get the takedown."
"Bobby Lashley couldn’t and cant take Cain down and he's leaps and bounds a better wrestler than Brock as well as just as big so don’t count Cain out in the wrestling just yet."
Thomson trains at the same gym as Cain Velasquez at American Kickboxing Academy in San Jose.