ADRF5721 and ADRF5731 compatibility of SEROUT pin with SPI Bus connected to multiple devices

I want to use this on an SPI bus with other parts.

Is the SEROUT line tri-stated OPEN when LE=High, and only driven when LE=LOW?

In other words, do I need to put a tri-state buffer or switch between the SEROUT pin and the MOSI pin on the bus master?

This info needs to be added to the data sheet.