Chazzan's Aneinu

During Shacharis, only the Chazzan recites Aneinu. Therefore, one who is not fasting (or who anticipates that he won’t be able to finish the fast) shouldn’t serve as Chazzan.

[In the unlikely event that the Chazzan won’t be fasting, or less than three congregants will be fasting: Instead of reciting Aneinu between Goel Yisroel and R’foeinu, the Chazzan includes Aneinu in the Brocho of Shema Koleinu, and concludes the Brocho regularly; i.e. Shomea Tefillah.]

A Chazzan who forgot to recite Aneinu:

• if he remembered before reciting Hashem’s name at the end of the Brocho of R’foeinu, he recites Aneinu immediately, and then repeats the Brocho of R’foeinu;
• if he already concluded the Brocho of R’foeinu, he recites Aneinu in the Brocho of Shema Koleinu, and concludes the Brocho with a double conclusion; i.e. Ha’one B’eis Tzara V’shomea Tefillah;
• if he already concluded the Brocho of Shema Koleinu, he recites Aneinu as a separate Brocho immediately after the Brocho of Sim Shalom.