When you say 'was pure dogshit', I presume what you meant to type was 'came on as sub after 65 minutes, and scored a great header to keep us in the competition'?
Probably. But that's not a reason, to hold onto him. Its costing us about £1m a season in depreceation and wages. I'd say that if he isn't working out for us, then carrying on spending that, just to prevent him scoring for someone else, really would make us mugs.