On your next payroll, you can make corrections on the timecard by entering a negative row at the top of the grid with the original date for the time that was NOT job costed, and then job cost it how it should have been.  Then put in the rest of your regular payroll and process.  This will put the employee and hours where they should be.  

Option #2:  Do the journal entry, then drill into the new job cost record and add the employee and hours and pay type manually to that record.