Editing the .vmx file worked for me. I replaced all existing "serial1" entries with this:

serial1.present = "TRUE"
serial1.autodetect = "FALSE"
serial1.fileType = "device"
serial1.fileName = "COM3"
serial1.tryNoRxLoss = "FALSE"

The VMWare GUI now says "Serial Port 2": "Using port COM3". Under Connection: "Use physical serial port" is checked with "COM3" in the drop down. COM3 wasn't available before.

The linux client maps the serial device to /dev/ttyS1.

Thanks for the help,

barry_hf