West Ham manager Alan Pardew says the arrival of Carlos Tevez and Javier Mascherano could turn the club into serious challengers for major honours.
The players' arrival has been shrouded in mystery, but Pardew says fans should stop worrying and be excited about how the players can take the club forwards.
"We want to go to the next level and challenge the big teams - this is a route to do that," he said.
"Let's forget the negativity over the transfer and look at the positives."
In his first full season in charge, Pardew took West Ham to the Premiership, and in the second he took them to a top 10 finish and the FA Cup final.
He said West Ham's rise had helped him bring the Argentine duo to the club - and he was hopeful they would propel the club even higher.
"We wouldn't be sitting here with these two guys if we hadn't had great success already," he said.
"We've improved rapidly in the last two or three years, we're in the Uefa Cup and now we've signed two world class players."
I will never be forced to play either of them - as has also been suggested. If that was the case I wouldn't be here anymore
Some have suggested the players are using West Ham as a shop window to help them win a move to a more glamorous European club.
But Pardew said the new signings would blend with the club's home grown talent and could produce spectacular results.
"The players we've produced at this club are second to none, and we're still producing them," he said.
"Our supply line has not stopped - but what do we want to be?
"I've said all along I don't want to be a mediocre club, that doesn't interest me.
"I want success, and I think we've done a pretty good job so far - now we've signed two great guys who will have to fight to get in the team.
"For a whole season we've got a great team, and at the end of that season we can review it.
"Hopefully we can have such success that these guys will stay with us, not just for one year but two, three, maybe even four years."
Pardew has also dismissed reports that he will no longer have full control of team selection following the arrival of the Argentine players.
"But I will never be forced to play either of them - as has also been suggested. If that was the case I wouldn't be here anymore."