I would give him a spin for a year.
Lomax FB and Walsh HB have had serious injuries.
They will both miss some games at the start of the season and will need easing in.
Wheeler has gone.
Therefore game-time at FB and HB would suit McDonnell.
Once up to speed he provides some proper cover and rotation for Wingers
as well as ongoing cover at FB/HB.
Dawson is more of a centre. Hohaia is needed at bench hooker in the main.
In a salary capped squad system a good utility to give some options
in a number of back positions would be good.
A one year deal for him would be good business.
I fear the sentimentality of fitting in Wellens may preclude this.