Torres has scored only nine league goals in 51 games since a 50 million pounds move from Liverpool in January 2011, struggling to live up to the British record transfer fee.
Fellow Spaniard Arteta, hoever, believes Torres has come in for some unwarranted criticism.
"I don't like the way he has been treated because I have known him since we were 16, 17 and I really appreciate him," Arteta told Arsenal's website.
"He is a friend of mine. Obviously, football is like that - it doesn't matter what you have done in the past, it is only what you have done in the last few weeks.
"He has been criticised. Mentally he is a really strong guy even if someone doubts him."
"When you play as a striker and they pay £50 million for you, you are under huge pressure," added Arteta, who also made the move from Merseyside to London when he joined Arsenal from Everton as a replacement for Cesc Fabregas.
"When the ball isn't going in the net, it is even more difficult because people always look at that.
"For a striker, sometimes it is not fair. For a midfielder or a defender it is a bit easier to adapt."
Torres did score in Chelsea's League Cup romp against Wolverhampton Wanderers on Tuesday, taking his total for the season to four, but the criticsm he received last season has surfaced again since the start of the new campaign.
Despite wishing him a return to form, Arteta said their friendship would be put to one side on Saturday when Arsenal try and inflict a first league defeat of the season on the leaders.
"Hopefully, he is going to get over that and it is going to become a better situation because it is not nice," he said.
"I talk to him a lot. When we were in Liverpool, we used to live next to each other and he is a really nice guy. Everyone would tell you the same.
"Even if he plays for Chelsea, I don't want something bad to happen to him. Obviously when it comes to the game tomorrow though, we are not friends."
