Be very careful with roto what you're looking to trade away and trade for. Will Upton's bat alone help you gain categories in HR/RBI/SB? If you can creep up 4-5 points, then this is something you want to look at if you have a significant lead in K's/W's.
You also have to remember that Cliff Lee is generally a better second half pitcher, so something to consider.
It's a somewhat of a fair trade I suppose in keeper leagues, but in one year roto leagues, you want a consistent power bat.
Keeper League:
F) N.Backstrom, E.Malkin, V.Lecavalier, P.Mueller, A.Mcdonald, B.Boyes, A.Hemsky, S.Horcoff, K.Turris, D.Jeffrey, M.Perreault, C.O'Reilly, S.Upshall, M.Erat, S.Gagne, D.Legwand D) S.Souray, M.Streit, A.Babchuk, T.Gilbert, I.Cole, J.Hillen, M.Methot G) B.Elliott, S.Varlamov, C.Ward, J.Reimer P) N.Kadri, E.Kuznetsov, S.Shirokov, V.Tarasenko, J.Blum, OEL, J.Moore, O.Pavelec