"We've got Wayne Rooney and Carlos Tevez but we need one more striker to win trophies this season," the nited left-back told the club's official website.
"Louis is the right guy for that job. In training he has been unbelievable.
"He looks sharp, strong and, most importantly, angry. You can see it in his eyes. He wants to do well.
"Louis has a strong mentality because he has suffered quite a few injuries, but he's still here and wants to do well.
"Now I hope his injuries are behind him. We need him if we are going to win trophies this year."