Spanish NFL announcer....

Last two sunday night nfl games I've had a spanish announcer calling the game. This is out of no where.

No announcement by the nfl, no explanation prior to the game. I've check all the tv settings with the

remote and the only settings for language (2) are both set on english.

Any suggestions? This is only happening on one air channel (nbc?)and only on these sunday night football games.

tia....