Gretna have lost eight goals in their first two games in the SPL.
And Irons is hoping that his latest signing will help plug the gaps in defence.
Aurelien Collin is set to make his debut against Hearts on Saturday after the 21-year-old completed his move from Real Mallorca.
"We obviously have to look at our defence after losing eight goals," said Irons.
"It is something that we have talked about as a team."