|There are steps you can take to possibly save a struggling employee, but if you expect him to fail, that is all but guaranteed to happen. As a result, regardless of the actions you take to attempt a turnaround, you need to approach the situation with the expectation that this employee has a real chance of succeeding.|
With that in mind, take a look at the coaching style that you are using with him. Be sure to give him feedback as close to his problematic behaviors as possible, and provide him with specific steps that he can take to prevent the problems from recurring. Since people learn in different ways, it may be helpful to try varying your coaching style to see if a different approach has a more enduring impact on him. For example, it may help if you actually model the behaviors that you want him to learn.
Another possible step is to assign a mentor to this employee. Perhaps with more consistent feedback and guidance from a highly effective co-worker, your struggling employee will find that it is less of a struggle to upgrade his performance.
You may also want to consider transferring this employee. It is possible that various aspects of the job, work environment, or even your leadership style are interfering with his effectiveness, and a lateral move may provide him with a real opportunity to avoid being ditched.