The phrase "to sign a replacement" means to officially employ or bring in someone new to take the place of someone else who has left or is no longer fulfilling that role.
Sentences with «to sign a replacement»
If not, lets sign a replacement who can score goals and who can play to the strengths of giroud. (justarsenal.com)
By signing a replacement form you are NOT canceling your current coverage, nor are you indicating that you have officially decided to do so. (lifesourcedirect.com)
So great, he lost our leading receiver to FA, but did not sign his replacement and signed terrible players to short term deals. (sbnation.com)