"Ve'eis ha'Keves ha'Sheini Ta'aseh bein ha'Arbayim". What if they did not bring the morning lamb?
Menachos, 50a: If they failed to bring the morning lamb, they did not bring the afternoon lamb. 1
As the words "ha'Keves ha'Sheini" implies. Though that only applies to where the Mizbe'ach was not yet consecrated . See Torah Temimah, note 33.
What is "Re'ach Nicho'ach" referring to?
Rashi: It is referring to the Minchas Nesachim (that is brought together with the Olah), which was burned in its entirety on the Mizbe'ach.