Isn't it the norm for an Arsenal player to have a 'mare on his debut?
Erm. No?
Chamakh scored on his home debut, forced the equaliser at Anfield on his debut, Koscielny had an excellent game against LFC on his debut, Vermaelen scored twice on his debut, Gervinho got a brace on his friendly debut and played well vs Newcastle tbf, Nasri scored on his debut...
Not sure where you got that from - give me some examples of Joe Cole-esque debuts?