Perhaps it's apt for a team who are dab hands at playing competitive fixtures during this time of summer to be experiencing friendlies with an extra edge.
Saturday's madcap 3-3 draw with Rapid Vienna saw Premiership champions Celtic face a team who were hell-bent on earning a result as if group stage football was on the line. And there was no time to relax for Ange Postecoglou 's troops as they jumped out the frying pan and into the fryer against Banik Ostrava on Wednesday.
The Centurions were celebrating their 100th anniversary and a raucous 15,000 crowd brought pyro...and a punch up with each other! Yes, several supporters were spotted getting handsy with each other before kick off. And they never let up even when Postecoglou's men piled up the chances and eventually the goals during an exciting 4-2 win over the Czech Premier League side. And that's not to mention the toilet roll that filled the pitch in the first half.