Access logging for replacePathRegex

Hello Team,
First of all I would like to say thanks for the great product!
My question is, if you have middleware like this for example:

http:
  middlewares:
    test-replacepathregex:
      replacePathRegex:
        regex: "^/foo/(.*)"
        replacement: "/bar/$1"

How can you see what is actually getting passed on? In other words, what does the new Path look like? This can be tricky if you have a complex regex.
FYI, I have enabled access logging with 'format: json' but it isn't in there.
Big thanks!

I can see before and after in Traefik debug log:

X-Replaced-Path: /xmas/12345
Path: /hohoho/12345

when using

  - traefik.http.middlewares.myreplace.replacepathregex.regex=/xmas/(.*)
  - traefik.http.middlewares.myreplace.replacepathregex.replacement=/hohoho/$$1