Diamond Valley + Groundbreaker

[arwall]

Diamond Valley says that it can be used after blockers are declared, so my question is this. If I attack with Groundbreaker and no one is there to contest the attack and Groundbreaker lives, can I then sacrifice Groundbreaker using Diamond Valley's effect and gain 6 life?

I'm assuming I can since it's not the end of my turn, and I'd be doing this in my second main phase.

[Sigar]

Toughness...

[arwall]

jgoirajp

Useless combo to me now unless I want to go out of my way to find a combo with Diamond Valley.

It'd be a nice combo but not for this.

EDIT: For the questions sake, could I do it?

I could just as easily use something to switch power and toughness and then sacrifice it.

[Pneumatiker]

Of course you can. The original card text was just added to make clear that you can block with a creature and even if you sacrifice the blocking creature afterwards, the creature it blocked still counts as blocked.

[Malchar]

The oracle text for Diamond Valley is now simply:
T, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=159124
So, you can activate it at any time.

[arwall]

Alright, cool.

Thanks.