Sissoko has frequently spoke of his admiration for Arsenal, but joined Tottenham in a £30million deal from Newcastle on deadline day.
Speaking about his France team-mate, Giroud told Le10 Sport: “I told him to give Arsenal the priority. It’s true it was special denouement. Until the end he didn’t know what he’ll do.
“It’s good for him. I think it was quite a long month for him so it’s good that something could have happened even in the very last moments. It’s great for him.
“Tottenham is a great team in our league. Obviously we all wanted for him after his good Euro and great performances, that he joins a Premier League club.
“In the Premier League Tottenham are an opponent for the trophy this year. I hope he will not be in good conditions against us.”