.sr-only within linked Headline element

I have a linked headline element with some text in it, but it needs to be differentiated for screen readers, so I’d like to add a hidden .sr-reader element. Is there any way to wrap a portion of the contained text with an .sr-reader span?

The element currently renders like this:

<span class="gb-headline-text">
    <a href="#mylink" data-type="page" data-id="402">My Link Text</a>
</span>

And I need this:

<span class="gb-headline-text">
    <a href="#mylink" data-type="page" data-id="402">My Link Text <span class="sr-only">Additional Screen Reader Content</span></a>
</span>