Kirwan was among the team's most productive players last season.
Saturday and Sunday's contests will still be played as scheduled and are set to begin at 4:30 p.m. on Saturday, April 13, and 1 p.m. on Sunday, April 14.
Allessie is a former All-American and All-Big Ten honoree.
Jack Posey and Kevin Parnham were key contributors on last year's team that reached the NCAA semifinal.
The Nittany Lions mercy-ruled Fairleigh Dickinson in a 4,902 program-record attendance.
The redshirt junior ranks fifth in Lady Lion program history in career steals.