Kirwan was among the team's most productive players last season.
The Nittany Lions mercy-ruled Fairleigh Dickinson in a 4,902 program-record attendance.
The game ended via the mercy rule in the seventh inning.
It appears likely that two Penn Staters will be drafted in the first round.
Rucci previously played for Wisconsin before transferring to Penn State in January where he has significant roots.
The Russian had a .918 save percentage last season.