The United States captain has joined WSL champions Manchester City on a short-term deal from Houston Dash.
United States captain Lloyd, 34, the 2016 FIFA Player of the Year and a two-time Olympic gold medallist, has joined WSL champions Manchester City on a short-term deal from Houston Dash that will see her stay until the end of the Spring Series in May.
Lloyd has won 232 international caps and scored a hat-trick, including a goal from 55 yards, in the USA's 5-2 win over Japan in the 2015 World Cup final.
England international Stoney, who moved WSL clubs in December when joining Liverpool from Arsenal, had no doubt about the importance of Lloyd's arrival.
"I think it is huge for the WSL," Stoney said. "To see players like her sign it shows just how far the WSL has come.
"I think there will be more, but for her to sign it is huge. It is massive for Man City and it is huge for players like me who get to play against her - they are the players you want to play against."
The defender added: "I absolutely cannot wait to play against her. You want to play against the best players in the world, if you play against the best then you know what level you are at.
"If you look at the players that have joined the league from abroad it shows the direction that league is going in."