Mattie was presented with his Hammer of the Year award before the Watford game and Peter says:
"In the short period I have been here he has been outstanding, there is no doubt about it.
"That been shown in the games he has not played in when we have struggled to replace him.
"He has been very positive in everything he has done, although there are improvements that can be made in his game.
"He is top quality and I remember playing for him for Reading against Peterborough, believe it or not.
"He'll not remember it - but I definitely caught him, that is for sure!
"He went from Peterborough to Tottenham and did very well there before coming here."
Peter admits that Mattie is a unique talent that is a real loss when he is missing, and adds:
"You have players in your team that you can replace or that you have someone similar to in the squad - but I must admit we have struggled to really replace Mattie at any time.
"We are getting close to it, because you look at young Chris Cohen when he has come in - in the last couple of performances he has been outstanding.
"But he is a different type of player, whereas with most players there is probably someone that can come in that does a comparable job.
"With Mattie there are not too many similar players like him about, never mind anything else.
"If you look at the national team, they struggle for left sided players, so it is not just West Ham.
"Hopefully he can help us to the Premiership and if he gets there, who is to say that if England have a problem on the left side Mattie cannot be vying for a position in that team?
"We understand just how good he is - and we still feel he is capable of a lot more."
Peter feels Matthew has physical strength to go with his obvious skills and adds:
"He is strong and powerful and he has played in the Premiership; he is not as weak as people would think.
"Some of the goals he has scored, holding people off after running with the ball, show that.
"A lot of people can run quickly with the ball but Mattie seems to do both in equal measures; he can run as quickly with the ball at his feet, making those direct runs.
"It a great ability to have, because it is not natural for a lot of players - he seems to always have it under control."
Runner-up for Hammer of the Year was Michael Carrick, and Peter adds:
"The one thing people tend to forget is that Michael is a young, young man and has had a lot of difficult times with injuries or whatever.
"Relegation wasn't an easy situation, especially with him being so young, because you wouldn't know if you were coming or going.
"A lot of his friends have gone on to the Champions' League, which is the sort of arena he wants.
"There is no doubt he has the ability to do it, but he has got to perform all the time.
"Technically he is as good as I have seen though he should be more forceful at times when he is in possession - he could just take people out of the game.
"He can look a wonderful player and difficult to stop; technically he would be lauded in foreign countries more than Britain.
"People can say he looks lazy as they did about Glenn Hoddle, but they tend to forget these players work so hard.
"He stays behind after training to work on his shooting or whatever and he wants to improve.
"If he can do that and keep clear of injuries the world could be his oyster."