I love Trevethan but we got guys that can replace him, they have been showing that.
Prince will be a little tougher to replace, but he is definitely a weak spot on D. Don't forget Haha is FA at end of season as well.
I personally would go
Rd 2 LT
Rd 2 DB
Rd 5 G
Rd 6 S
Rd 6 Best Player Available
Rd 7 K