He now misses the crucial game at home to relegation rivals Portsmouth on Sunday, April 25.
Viduka said: "What I did at the end was a silly thing, stupid. I didn’t think I was going to get sent off for it though. To be honest all I was trying to do was kick the ball back to Leicester keeper Ian Walker.
"Now I’ll miss the Portsmouth game, which is a vital one, and I’ll just be wishing the lads all the best. Hopefully, they’ll be able to do the business in that game without me."