It is one drawback to the Pro Am that some players do not show up for every game. The rules are that teams are open, and all players appear to be able to choose when they will play for their team, and which games they will miss. However, there are always enough players to make up the teams, so the coaches must be doing some organizing before games to make sure this is so. It is a very short season, seven games long, plus a few playoff games. Some of the better known pro players may show up for a game at the end of the season, or for the playoff games, presumably so they can play against the best competition. Guys like Kiwi Gardner show up for every single game.
One thing that may contribute to the lack of NBA players in the Pro Am now is the fact that the NBA Summer league in Las Vegas runs from July 11-21, and overlaps with the Pro Am season, so naturally the NBA grade player would rather compete in Las Vegas, because the competition is better.
As to Cal players, Justin Cobbs played in all his team's games last summer, up until he fractured his foot. I believe Robert Thurman played in all his team's games in the last two summers, and I think Jeff Powers played in most of his team's games. In the previous summer, Ricky Kreklow played in over half his team's games and Richard Solomon did as well. Some pro players arrived in time for the playoffs, and when they did, Richard's playing time was severely reduced, and I don't think he played after that. In that same summer, Tyrone Wallace and Kahlil Johnson were listed on team rosters, but they never showed up at all for any games.
The Pro Am is run entirely by volunteers, and there are very few of them. Last season they did not have anyone to keep stats, so there were none kept. The rosters don't list the players' numbers, so unless you recognize a player's face, you have no idea who he is. The PA system is so bad it makes the Haas system sound like Carnegie Hall, and when the announcer calls out a player's name, it is so garbled, it is unintelligible.
In spite of all this, I take serious issue with those would denigrate the league as worthless, and say things like players just play in it to hone skills or get exercise. You can hone skills at the hoop in your backyard, like Richard Solomon chose to do last summer, and you can get exercise by running in the hills like Roger Craig or going to a local fitness center. No, the players who play in the Pro Am games come there for the competition. The games are fiercely competitive. Witness Justin Cobbs and his broken foot. The players go all out. It doesn't have the defined structure on offense and defense that D1 ball does, nor does it have the best coaching, but there is a great deal of teamwork going at both ends of the floor by very experienced players. Players may try to work on some new shot, like Richard Solomon tried to perfect his three point shot, but by and large it is intense mano a mano stuff, like Robert Thurman against Dwight Powell, and fun to watch.
My only suggestion is if you want to see a particular Cal player, then watch the Pro Am website and the Bear Insider, and wait until that player has actually appeared in his first game, before you venture to one of his team's games. That way, at least you will know he is an active player, and not a no-show for the entire season like Wallace and Johnson were. Still no guarantee though. It is a sad state of affairs for a league that once was a big draw for local hoop fans.