If you want to identify the physical NIC which matches up to the virtual NIC in your ESXi Host, you can use Ethtool.
Just fire the following command on your ESXi host to make the physical NIC blinking:
ethtool -p <devicename> <time-in-seconds>
eg. to make vmnic0 blink for 60 seconds use:
ethtool -p vmnic0 60
By the way, to list the status of your pNICs in your ESXi host use:
… and you will get an output similar to this: