Filter items from an array based on input with wildcard

It's easier with zsh:

$ array=(saf sri trip tata strokes)
$ pattern='*tr*'
$ printf '%s\n' ${(M)array:#$~pattern}
trip
strokes

• ${array:#pattern}: expands to the elements of the array that don't match the pattern.
• (M) (for match): reverts the meaning of the :# operator to expand to the elements that match instead
• $~pattern, causes the content of $pattern to be taken as a pattern.

One way to do it:

array=(saf sri trip tata strokes)                      
input=*tr*
for foo in "${array[@]}"; do
    case "$foo" in
        $input) printf '%s\n' "$foo" ;;
    esac
done

Note to the overly enthusiastic quoters: the right-hand side in assignments (such as *tr* in input=*tr*) doesn't need quoting.