You haven't lived until you ruptured an Achilles, now THAT'S an experience I wouldn't want to wish on anyone.
nothing warns you about it, no amount of warming up or stretching prevents it, it just happens.
I was playing competitive soccer (masters) when I felt what I thought was a hefty kick to my leg after winning the ball in a contest and took off with it.
I quickly turned around to my opponent and asked WTF?
He looked incredulous and denied touching me. It was only then I realised it wasn't him when my foot just flopped and I couldn't balance on my left leg.
Anyways a trip to hospital emergency at the epworth in melbourne (never use a public emergency pay the $300 and get treated in less than an hour) plastered up and then surgery a week later, 4 months on crutches and a further month walking in a boot and finally physio. 18 months later and all is good again. This was in 2009, and now back to better than before.
the one thing I found strange was the lack of any real pain.
Good luck with the calf tear it will heal!!
