Speaking on the official West Ham web site Tevez has revealed he has knowledge of West Ham through his close friend Lionel Scaloni.
"I first heard about the possibility of joining West Ham United 48 hours ago. I had followed the club quite a bit last season because I am a close friend of Lionel Scaloni. We watched every West Ham game in Argentina because of our friendship and he spoke very highly of the club, its supporters and the manager.
Yes, it's true, other clubs in the Premier League and around Europe were interested in signing both myself and Javier. But when we met Alan Pardew the choice was simple - he made us both feel really wanted.
I know there will be a lot of fuss around us because we are two new players from Argentina, but we see ourselves as team players, not individuals. That was another attraction for coming here - Mr Pardew explained that there is a great team spirit at the club, and we want to be a part of that.
When you are thousands of miles away from home, team-mates become like family, and it is important to have a good spirit - it shows we are all working together. We both want to learn English, because it is important to integrate with the team and our new colleagues."
Mascherano also spoke of his liking of Pardew,
"Mr Pardew's enthusiasm rubbed off on both of us. He talked about his vision for us and the club, and we both became very excited. He is organised, with a clear idea of what he expects, and I was very impressed with his approach.
I am also aware of some of the great players at West Ham. I know of Anton Ferdinand - he is talked about a lot in Argentina as a great player of the future, while I also like Nigel Reo-Coker, who is a very dynamic captain and displays the work ethic that is clearly in place at West Ham.
We also like the sound of English football being quicker, with a lot of pressure. We will both improve as players because of that. And I am excited about playing in the UEFA Cup. In Argentina, European competition matches are watched with great enthusiasm, and it will be a wonderful experience for us."
Tevez will wear number 32 on his West Ham top, while Mascherano will wear number 16. The first question they asked upon being presented with a West Ham United shirt was: 'Tell us about the Hammers - where does that symbol come from?', while as Chairman Terence Brown revealed, Javier even asked to be given the number six shirt because of Bobby Moore.