Can I make my Co-Worker work later?
Isn't he working hard enough to begin with?
He isn't doing a great job.
It is wrong to keep people working past their scheduled hours. You cannot force people to work more, you can fire them and replace if it such a bad job.
If I do that, I'll get fired.
It doesn't matter what you have happening there your coworker probably has responsibilities he also has to tend to other than work.