Allen, 27, played 56 regular-season games for a Grand Rapids Griffins team that went on to win the Calder Cup in 2016-17, collecting one goal and 10 assists for 11 points.
A native of Chicago, Allen has skated in 267 career AHL games over four professional seasons with Hartford, Milwaukee, Binghamton, Iowa and Grand Rapids, totaling 21 goals and 69 assists for 90 points.
Undrafted out of UMass-Amherst, Allen has played seven career games in the National Hockey League, all with the New York Rangers.
Gill, 25, completed his fourth professional season in 2016-17 and posted AHL career highs with six goals, 12 assists, 18 points and a plus-6 rating in 44 games with Wilkes-Barre/Scranton.
Gill has played 102 career AHL games with Wilkes-Barre and Hamilton, compiling 14 goals and 25 assists for 39 points.
A native of Terrace, B.C., Gill played three seasons at Boston University.