Disclosed are compounds of Formula (I) Formula (I) or salts thereof, wherein HET is a heteroaryl selected from oxazolyl, pyrazolyl, imidazo[1,2-b]pyridazin-3-yl, and pyrazolo[1,5-a]pyrimidin-3-yl, wherein said heteroaryl is attached to the pyridinyl group in the compound of Formula (I) by a carbon ring atom in the heteroaryl and wherein said heteroaryl is substituted with zero to 2 Rb; and R1, R3, and Rb are define herein. Also disclosed are methods of using such compounds as modulators of IRAK4, and pharmaceutical compositions comprising such compounds. These compounds are useful in treating, preventing, or slowing inflammatory and autoimmune diseases, or in the treatment of cancer.