PSU will be the decided underdog in their semifinal. During PSU's return, over the last 5 years, to national prominence in WLAX, I'm pretty sure Maryland has been the only top team that they have not been able to defeat. The two teams played late this regular season, @ PSU, and played a really tight game, but MD won 16-14. That was the most goals scored against MD during the regular game, and MD's closest margin of victory during the regular season. (Hopkins scored 16 point against them in the B1G Tourney, and and they defeated Stony Brook by only 1 point in their NCAA Quarterfinal match.) Last year, PSU fell to MD, @ MD, 9-10. PSU fell to MD in 2015, 10-13.
To some extent, PSU can only blame themselves for having to face MD in the semis. If they had beaten Northwestern in the B1G Tourney semis, they may well have gotten a #2 or a #3 seed in the NCAA, and thus would not have faced MD until the final.
Returning to MD, they are undefeated on the season, and have defeated almost all of the top teams during the regular season and postseason. They met and defeated the following teams that were seeded in the NCAAs:
#2 UNC - 13-10
#3 Florida - 18-8
#4 PSU - 16-14
#5 Princeton - 18-12
#6 Syracuse - 17-7
#7 Penn - 11-7
#8 Stony Brook - 13-12 in NCAA Quarterfinals
The NCAA only seeds the top 8 in WLAX. MD also defeated BC, who is in the other NCAA semi against Navy, 21-13 during the regular season.
Then again, that's why you play the match. MD was the favorite in last year's NCAAs, but lost to UNC. MD was also the favorite in the 2015 B1G tourney but were defeated by Ohio State in the semis, and PSU went on to win the tourney.