If by "mop head" you mean a standard plant in a pot (i.e. a long stem with then green growth at the top) then yes, cut the suckers off. They will spoil the appearance of the plant and not do it any good. Try to cut the suckers off as near where they first appear on the stem as possible. A little gentle probing under the surface of the soil may be neccessary.
. The Bay tree is growing outside. I have had it for about 14yrs and have trained it into a mop head.
I shall cut off the suckers which are growing from below ground. Any particarlar time of year..to possibly see if I can root them after severing from the mother plant?