The /ʌ/ vowel is spelled with <u> and <o> in worry. The /ɪə/ vowel is spelled <ear>, <eer>, or <ier>.
This is a contrast between a short vowel and a diphthong widely separated in the mouth. It does not seem to be a problem for learners.
bud beard budded bearded budding bearding buds beards buzz beers does dears Durham Dereham fuss fierce fuzz fears pus pierce spud speared stud steered unworried unwearied us ears worry weary worried wearied worries wearies worrisome wearisome worrying wearying