Do the replace if you can.
On the other hand these are ‘only’ read errors which is not that bad. If you write to that sector then you can be only sure if it has defects.
I would run the vendors utility to check (they also run smart tests) if it has problems. They usually make bootable cds available.
You can and should run a self test which you can do from linux by issuing
smartctl -t long /dev/your-device
wait a couple of hours (it will show an estimate). Then check again with
smartctl -a /dev/your-device
If it says
Completed without errors you are fine. If not go for the vendors utility to check the drive.