"Those to me were tremendous plays," Manuel said. "I felt, 'Wow, if I can get some of that, it could save us a ballgame at the end.' I try to do what is best to win the game."
The first instance came after Delgado dropped a bad throw from Jose Reyes in the seventh inning Sunday, and Manuel replaced him an inning later with Tatis. Manuel said that had been the plan all along.
Tatis, a natural middle infielder, has shown more range than Delgado at first base this year, giving Manuel more reason to play him. So as long as Delgado isn't due up in the batting order, he will spend the final innings of most tight games on the bench.
Manuel gave Delgado a quick primer on the situation during Sunday's game, then later explained his reasoning in full.
"I explained to him, the professional that he is, the man that he's been since I've been here, the respect that I have for him," Manuel said. "I explained to him, hoping that he would understand -- which he did -- but knowing that he wouldn't like it."
Delgado affirmed after Monday's game that he understood.
"He spoke to me, and I don't have a problem with it," Delgado said.
Anthony DiComo is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.