If he signs he will be brilliant until he makes his first mistake - and then most will want him dropped
Listening to the south american football expert on sky (can't think of his name), he said that Martinez would only sign for a club who would guarantee he will be 1st choice, as he wants to be the Argentinian national team goalkeeper.
If he were not 1st choice with us - why would he leave Arsenal? he may as well sit on their subs bench