To slip a pass is to give a short pass to a team mate. The idea here is that there is not much space but the player still manages to find a team mate (so Messi passed to Neymar).

I am not sure about the phrase 'caroms off' I have a feeling it might mean blocked but it may be a misspelled word.

Thanks so much, Damian. I have also been reading more about "The Good, the Bad and the Ugly". My football vocabulary increasingly improve and I know them a lot now. 🙂

Slip a pass means to give a short pass when you are under pressure - it is a clever pass that needs skill. To cannon off, means to rebound, so in his case, the shot hit De Rossi and bounced back: cannon is a kind of large gun, so the nuance here is that it is a powerful shot!

Ah yes, to cannon off someone or something. So the shot from Messi hits De Rossi very hard and bounces away.