the answer to your question depends on
a) the exact model of your adapter (There are a number of LPe11000 adapters listed in the VMware HCL, and not all of them are supported with ESXi 4.1)
b) whether it is an original Emulex adapter or 3rd-party-branded (IBM/EMC/Sun)
To find out the exact model find out the PCI ID and compare it to the entries listed in the HCL.
As a starting point you can refer to the Emulex page here:
- Andreas
For all I know, you can always examine and give it a try. I am sure that you will surely get back and restore everything if it fails.