I'd never go target minutes while running the press - even if its a combo. Never. Just start him, give him little to no distro and sub him out at FF while his back up is set to tired. He will probably play 20 mpg or so, but shouldn't hurt you to much. Almost every season I'll start 1 or 2 FR just so I can have some starting level players come in off the bench. You can bench him again come CT time, but make sure his WE is back up to normal before you do. After practices stop, so does having to live up to promises.
At the end of the season he will e mail you and say thanks and that he'd knew you could make it right or whatever. His WE will go back up to where it was. His potential isn't bad if you just need an athletic rebounder who can play solid def. IMO, I don't think you needed to give him the promise. If you sign him with it, I think you could have signed him without it. Its worth about 1 home visit at best.