It was exactly how you called it. Klopp has admitted Matip played when injured and with fitness issues for the good of the team. He said wirh the injuries they had he had to put him in the side asap.
His body has proved time and time again that it can't cope with the rigours of the Premier League but it didn't stop them trying to completely break him.
You really would struggle to find anyone who wouldn't have seen this coming.
		
		
	 
You could tell he has been doing that, not just with Matip but loads of the players, and likely did so at Dortmund too. The difference is, Matip can't take it.
Any time a player is injured and they come back, there's never any easing them in, they are just thrust straight back in. Eventually it catches up with people. If the body is protecting say his thigh, it puts more strain on other aspects of the body, which them break down.
Same with Fabinho, who probably needs 3-4 weeks to get over this injury, then probably 2-3 to get back to full fitness. What odds he's just thrust straight back in against City?
What you see with most footballers, once they start getting injuries it tends to continue. It's the same as anyone else really, you've probably noticed, once you get say a knee problem, or achilles or whatever, it rarely properly recovers. The level of intensity he demands, in training and matches contributes negatively.
On a slight aside, you see the same with Harry Kane. Each time he does his ankle/knee/hamstring etc the body just gets weaker. 
I'd be very surprised, in honesty, if any of Gomes/Matip or VVD came back to full fitness and returned to the level they were at before. Whats more likely is they go the posh boy Chamberlain route, and the body starts to hamper them.