In 2v2 games, if I use Portal Rescue on my teammate's Mindsplitter, will the 'When you play me' effect trigger?

Ruling: Yes, the 'When you play me' effect will trigger. The owner (your teammate) is the one playing it, and it is getting played.

Nuances:

• Portal Rescue was errata'd to include 'owner' text, clarifying that the owner of the card is the one playing it even when another player uses Portal Rescue on it