Inversion with "as"

[ultrasuper]

Hi, the inversion (as will I) in the following sentence is obligatory or not ?
Gregory will play in the tournament this year, as will I
Can I say
Gregory will play in the tournament this year, as I will

Thanks a lot.

[Tdol]

It's obligatory there, IMO.

[ultrasuper]

How about this one:
He did not need to keep moving house, as his father had.

In this case, no inversion.

It is a sample given in Longman Dictionary of Contemporary English (http://pewebdic2.cw.idm.fr/), under "as, conjunction"?

[Tdol]

It's the negative, IMO:
Gregory will not play in the tournament, as I will.
Gregory will play in the tournament, as will I.