The 21-year-old has since agreed a three-year deal with Bolton's Premiership rivals Portsmouth, subject to a work permit.
Allardyce told the club's official website: "Collins left as he wouldn't train with us for a few days and that is all we asked.
"I had very little information about him other than a couple of videos or DVDs on him and that wasn't enough for us to take a gamble, even though he's a goalscorer.
"The amount of money that the whole package involved, for what we knew about him, was too much. I am not saying he won't be a good player, or a bargain, but we can't take that risk."