It really depends on the back. If he's pain free and it some thing that will effect him 10 years from now go get him, then trade him when his stock is high and let the second team deal with the back.
If he is in pain, pass, take it from some one that was athletic and developed back pain from work, you can't move any more, loose motor skills, and jumping is just gone, especially quick jumps like you would use for put backs.