As far as the rules are written, YES. However, it sometimes happen that it is actuelly better to play a Onfield player out in goal than to have your star GK.
My gaming groupe has ruled that NO onfield player is allowed to START in goal (ie. but if GK sent off then it is ok). You must then either: a) quickly buy/loan a new GK; or b) play a yourth team GK (rated 5.5)
An other house rule we tried (but didn't keep for numerious reasons), is to have a -2 stat penalty.
Of course you are more than welcome to come up with your own house rule. Just let us know how it worked out!
Yeah - sounds good. I also think you shouldn't be allowed to start an outfield player in goal. Not playing loans so will have to hope for transfer or play a youth team member. Think that should be 5 not 5.5 though. This is going to be a tough game!