Isaiah 49:3

Yahweh called His Servant Israel. Israel would indeed prove to be an instrument of God by which He demonstrated His glory, but in the context, the Servant appears to be an individual. Messiah was Israel, in that, He was the personal embodiment of ideal Israel, what the nation should have been but never attained. Furthermore, He was the Prince with God that neither the nation nor its namesake ever fully became. When God referred to His Servant as Israel He was referring to the Servant’s function, not His identity. Throughout this book we have seen that the nation Israel was not able to carry out her function of being a light to the nations because she was blind, deaf, and rebellious. God would provide an individual to do what the nation had failed to do.

"Faced with Israel’s failure, God does not wipe out the nation; he simply devises another way in which Israel’s servanthood could be worked out: through the ideal Israel." [Note: Oswalt, The Book . . . 40-66, p. 291.]

This description eliminates Isaiah or any other simply human prophet as the possible Servant in view (cf. Isaiah 49:5-6).