The reigning MLS Coach of the Year praised the league's attacking talent and said he was forced to omit some deserving players.
As coach of the host club, Porter will take charge of the representative side, and was allowed to select 10 of the 23 names in the squad. He chose Bill Hamid (D.C. United), Aurelien Collin (Sporting Kansas City), Chad Marshall (Seattle Sounders FC), Michael Parkhurst (Columbus Crew), Osvaldo Alonso (Seattle Sounders FC), Tim Cahill (New York Red Bulls), Will Johnson (Portland Timbers), Jermain Defoe (Toronto FC), Robbie Keane (LA Galaxy) and Bradley Wright-Phillips (New York Red Bulls).
Commissioner Don Garber added Portland midfielder Diego Valeri and Chivas USA striker Erick Torres with his two picks.
Despite Portland having the second-worst points per game in the Western Conference, Porter joked about wishing he had more spots for his own players.
"I wish I had more Timbers on (the roster)," laughed Porter when asked about his roster selections following Portland's 2-1 win over Colorado on Friday night. "I'd put a lot more Timbers on it if I could.
"It's a group of guys that have earned it. More than anything within the game, I felt it was important to reward guys that have earned it. There are a few guys from around that league that probably earned it that aren't going to get on, but at the end of the day, you've got to draw the line."
At least indirectly, Porter appeared to address the team's highest-profile exclusion: Sporting Kansas City forward Dom Dwyer, whose 14 goals have propelled KC into first place in the Eastern Conference.
"There are a lot of good players in the league, and a lot of attacking players that have been having good seasons," said Porter. "If I picked all the players that earned it, I'd be playing a formation that wouldn't work in the game, with too many strikers.
"But I still took more strikers than probably I should have."
The MLS All-Stars will take on Bayern Munich on Aug. 6 at Providence Park.