"I'm going to try to keep all those guys fresh down there," he said.
Cisnero, a rookie, has gone 2-2 with a 2.59 ERA with 36 strikeouts in 31 1/3 innings since May 11, and he has taken on an increasingly important role in the bullpen. Fields (1-1, 6.23) is a Rule 5 pick who's yet to pitch in a save situation this year.
Both Lo and Zeid made their Major League debuts earlier this week. Lo was closing games at Double-A Corpus Christi and had six saves in 17 appearances between Corpus Christi, Class A Quad Cities and Class A Tri-Cities. Zeid had 13 saves at Triple-A Oklahoma City.
"It may be Fields one night, it may be Lo the next, it may be Ciserno," Porter said. "It all depends on usage moving forward and where we are in the lineup in that game."
Porter was asked if his closer-by-committee approach allowed him the freedom to use his most effective reliever prior to the ninth inning, instead of being married to the closer working the ninth, when the game might not have necessarily been on the line.
"Sometimes I think it can help" he said. "But I would love to have Mariano Rivera, and it doesn't matter who's coming up or what the situation is. If it's a save situation, I'm going to hand the ball to him and cross my legs and be ready to shake hands."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.