Defender Keogh, midfielder Hendrick and striker Sammon are part of a provisional 28-man squad, having all won their first senior caps earlier this year.
Ireland take on England on May 29 before another friendly against Georgia in Dublin on June 2.
Those fixtures will act as a warm-up for a home World Cup qualifier against the Faroes Islands on June 7.
After that, Giovanni Trapattoni's men fly out to New York for a friendly against world and European champions Spain at Yankee Stadium on June 11.
Keogh, Derby's player of the year, won his first full international cap as a substitute against Poland in February.
Hendrick and Sammon also made their debuts on the same night in a 2-0 success against Poland at the Aviva Stadium.