Soccernomics: Grass?

The announcement that the Portland Timbers will take on English Premier League side Manchester City at Merlo Field at the University of Portland rather than at PGE Park makes me suspect that Man City would not agree to play on a turf field.   Merlo field holds less than 5,000 spectators meaning the opportunity cost of playing there is probably about 10,000 lost ticket sales.

One hopes that these economic realities will eventually cause the Timbers to try and facilitate a switch to grass, but it seems like it will take a good alternative for high school football to do so.