Again, not understanding this obsession with Giroud as if he is the missing link. He was awful in the FA Cup final and was taken out of the game by David Luiz. Even more recently against Spurs, he offered virtually nothing.
He should be used sparingly against specific opposition. I would've brought him on after we've taken the lead against Saints so our back line could protect the lead by playing it long to Giroud instead of risking playing it out from the back against Saint's press.