Tim Duncan is still one of the biggest problems for the Lakers, especially defensively. He'll guard both Howard and Gasol over the course of a game. Getting him into foul trouble (no easy task) would be a boon for the Lakers.
If Gasol and/or Howard can defend Duncan without requiring help from their teammates, the more difficult the game can be for the San Antonio shooters.
In Game 1 the Spurs shot 37.6% and Duncan had one assist with three turnovers. They also held him to 17 points on 6-15 shooting.