"He is a very nice guy, is intelligent, a nice person and I enjoyed being with him, even if it was for only a short time," Grant told BBC Radio 5 Live.
"Does he have the experience? No. But the authority? Time will say. I think yes.
"Football is a game of results, experience is important but more important is the quality and the authority to take a team and move it forwards."
Grant added: "When I saw Porto and how the players behaved towards him, the players liked him and he had authority, so he can do it also here.
"At the end of the day, players are human beings and if they see that he has the quality to take them forwards, they will respect him."