The 25-year-old winger joined West Ham from Championship outfit Nottingham Forest in the summer transfer window.
Prutton, himself a former Forest midfielder, played with Antonio at Wednesday, and he simply cannot speak highly enough of him.
“He was a tremendous team-mate because of the attributes that he's got," the 33-year-old told Sky Sports. “He’s tremendously strong and quick. He's just so direct.
“When you're at a team like Wednesday were at the time, what you want is that kind of outlet like Antonio who can carry the ball 40 or 50 yards up the pitch. He was a massive player for us.”
“He'll have to harness his performances for the team but he can do that and it's all part of the learning curve."
Good signing for West Ham United
Antonio is a highly-rated winger who was one of the best players for Forest last season.
The former Sheffield Wednesday player scored 14 goals and created 62 chances in 46 Championship games during the 2014-15 campaign.
The 25-year-old former Reading man had a pass accuracy of 60% and a shot accuracy of 44%, and won 151 headers, 104 dribbles and 42 tackles.
Antonio scored two goals and created nine chances in four Championship matches for the Reds this campaign before his move to West Ham.