IF you lay out your team rules we'll have a better understanding of the situation and be able to give you better advice. No way in a one-year or keeper I'm trading my Rask/Price/Lundy for Anderson. If the league rules are such that I have a bad team but am rebuilding and could trade my Rask this year for Anderson and can keep Anderson then maybe but I need to know how many I can keep and which players I can and can't keep.
From your perspective if you're in first place and win now mode than dealing Anderson for Rask/Price/Lundy is a huge upgrade this year and enough to put you over the top then I would most likely pull the trigger but again it depends how much this hurts you in future years.
Give us some context to help you out.
12 team H-2-H 1 year league, daily roster changes, 3 goalie start minimum/week
2xC, 2xRW, 2xLW, 4xD, 3xUtil, 2xG, 5 Bench
G, A, P, +/-, PIM, PPP, SHP, GWG, Hits, W, SV%, GAA
C: Backes, Ribeiro, Couturier, B. Nelson
LW: Galchenyuk, R. Nash, Kreider, Johansson, Pearson
RW: P. Kane, Voracek, Wheeler, Atkinson, Frolik
D: Byfuglien, Ghost, Hamilton, Gudas
G: Fleury, Dubnyk, Talbot