Yes, although I haven't played position lock in a bit, I want to say it was just pressing the same button that would cause you to pass if you had the puck (R2 on PS3). There is also a button that causes the CPU to shoot the puck (I want to say this was R1 on PS3, but not 100% sure)
I try to not call for a pass too often because once in awhile the CPU will make an amazing pass at just the right time. One thing I've noticed though, if you let the CPU carrier enter the zone, he'll shoot it 99.9% of the time. So you can work around this AI flaw by calling for the pass immediately. If I'm carrying the puck over the line I usually pass it first, which lets you ignore the other AI flaw of being allowed to waltz in alone too easily. Playing locked gives me a much more sim like experience than controlling the traditional way.
Something else I've noticed about playing locked in the attacking zone. The CPU wants to pass to you when you are below the slot. If you are above the slot, don't count on getting a pass without you calling for it.
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