Another citrus plant is coming from Mandarin plant.

Hi there, bought Mandarin plant this year in July. Recently i noticed that new leaves r appearing from the mandarin plant, but they are different. After a thorough research on net, i came to know that another citrus plant known as Trifoliate orange is this one. I guess this plant was used for grafting the mandarin. My question is this; should i let it grow along with Mandarin or trim it. I know two or three citrus family plants can grow together from main plant. In my case , main plant is Mandarin.
Wish i could attach the pic here.
Tnx