I walked and trotted him out to look at how he moves, and looked at him coming straight on and from behind. His left front leg is a little larger than the other one in the region where the superficial digital flexor tendon is. I ran my hands over both front legs very thoroughly, and nothing produces heat or pain, and there is minimal scar tissue. I checked for signs of surgery or scars from pins, and there are none, so I'm guessing a bowed tendon.
The owner was not super forthcoming with information besides sending him to the trainer, and that he raced before being properly conditioned and on a rough track, causing the injury. He hasn't been ridden in a year, and I did ride him and he was OK, but off on the opposite leg of the tendon issue. She told me that was a fluke, he hasn't been lame and she has no idea why he would be off on the opposite leg. I figure she's being honest about that one, and possibly he tripped. His conformation is pretty good, he has longer femurs and high set hocks, which seem to make it difficult for him to break over. He did trip once, and the foot with the old tendon issue was flipped down which raised some red flags for me. I really don't know much, but could that mean that the tendon was severed and never repaired? I haven't seen too many horses trip and land with the hoof facing downward, but again, that could have been a fluke. Even though he was a little off, he rode sound and did good walk and trot transitions.
Is it worth me bringing a vet out for, or should I pass on this horse completely? I have a good farrier who can help him break over more, and I'm willing to bring him back slowly, but I do like to ride fast, just mostly trotting and cantering, no galloping. He's just so nice, and REALLY cheap, I would like to weigh out what others think before I decide to do a vet check or not.