serve as a/(one's) replacement(redirected from serve as their replacements)
serve as a/(one's) replacement
To take the place or fill the purpose of someone or something else. We created these wood pellets from repurposed sawdust to serve as more a ecologically friendly substitute for other fuel sources. This is Shawna, everyone. She's going to be serving as my replacement while I'm on sabbatical.
See also: serve