Can you instantiate a GameObject that is already in the scene in photon networking?

I have a player GameObject in a single player game.
At any time the player can choose to go to multiplayer mode.
When a player chooses to go to multiplayer mode his player stays at the same transform so no change is needed to the player.
Therefor I would like to now if there is a way to instantiate a player object on the network using photon networking without removing the player from the scene.
For example when I use:

PhotonNetwork.Instatiate(“Player”)
It just creates a copy of a prefab onto the scene.
I would like to know if there is a way to instantiate my player object onto the network using my current player object in the scene.

Yes, PhotonNetwork.Instantiate(…) creates a new instance across the network, however you can use that to achieve what you want.
Therefore use the position and rotation of your SP-Character in the instantiation call. After having the MP-Character created just disable the SP-Character temporarily until you need him again. Before exiting multiplayer mode re-activate the SP-Character and update his position and rotation, because when exiting multiplayer mode the instantiated MP-Character gets automatically destroyed.