DeMarcus Cousins is the Warriors starting center but he hasn't played a single game this season. When he comes back, the Warriors will be the best possible team they can be but until then, opposing teams have taken advantage of the Warriors lack of a true center.
Lopez should fix that issue and give the Warriors a much-needed big body to clog the hole. He can also help the Warriors with shot blocking and while the Warriors are a great shot blocking team, having a player whose job is to block people will help them in the long run.
The great thing about this move would be that even after Cousins comes back, the Warriors will still rely on him. Head coach Steve Kerr is known to tweak lineups depending on match-ups. With a player like Lopez on the roster, the Warriors can try out new lineups against teams that like to play big.
Getting Cousins put the Warriors over the edge but this move might be checkmate. He may end up being the last piece to the puzzle that has been the Warriors lineup this year. Kerr has had to rely on young players with little experience to fill in big shoes and that hasn't worked out well for them. Now, a veteran will be filling in those shoes and the shoes will fit well.