Issue API response missing related merge request count

Web version issues list item displaying related merge request count:

But according to api, it only returns downvotes, upvotes, user_notes_count and there is no related_merge_request_count. I have to fetch list of all related merge requests with separate api call /projects/:id/issues/:issue_id/related_merge_requests, but it reproduces too much api requests.

Can related_merge_request_count be added to Issue as downvotes, upvotes, user_notes_count?