It's not a football-related idiom at all. It's effectively just a "one-off" usage.
Actually, to me it comes across as something of a bungled "mixed metaphor", because I understand cracker as alluding to Christmas cracker and firecracker (as well as the idiomatic slang usage cracker = thing that is very good). But Christmas crackers don't have triggers (two people pull them apart, one from each end, to "detonate" them), and firecrackers have fuses, not triggers.
Perhaps I'm a bit harsh. But all the writer means is the player started the play / attempt to score. Metaphorically, he suddenly / unexpectedly started to unleash his "offensive / attacking" power (his playing skills), the way one might pull the trigger / open fire with an actual offensive weapon (gun).