In the Project Bar there should be a Families folder, create a new family consisting of your Player and Object (assuming they are both the same object type, which I'm assuming is Sprites) and then name it whatever you want (i'll refer to it as ZOrderFam)
Then in the event sheet add an "ordered For Each" loop that runs every tick. Setting it to go through each object in the family in Ascending order by their Y value will make the actions start with the uppermost object and end with the lowermost one. Then adding the "Move to top of Layer" action will sort them and make the lower object appear in front of it.
(side note this was in Construct 3 rather than 2 so there may be some differences between them but I'm pretty sure 2 has all the features I used in this example)