The Office Elves

When this morning we all arrived at the office, we noticed that some has been playing foosball after hours. This is a picture of the crime scene:

In order to solve this mystery, the Office Elves will need your help! What we know already, due to evidences left at the location, is that the blue team consisted of Ásta and Stefán. But who was playing against them.. ? Any clues?

I am the biggest poop in Europe!!
-Ásta