Big dynasty league trade, dont know what to do

In my H2H points dynasty league I was offered Matt Holliday for my JUpton and Starling Marte. Upton rarely starts for me unless I have too many other OFers off that day and Marte is still in my minor league system. We start 4 OF with my starters being Kemp, McCuthceon, Hamilton, Melky. Although Im pretty set in the OF, I guess I would put Holliday in at my DH position. I usually rotate HanRam, Ichiro, Upton, Sandoval, Lawrie in that position.....basically whoever is the hottest hitter at the time. If i did this trade, it would cement Holliday (a top 10 hitter) into DH spot. What do you guys think? Im going for my third straight title this year and would love to win, but dont want to totally screw up my future. C: Santana 1B: Pujols 2B: Pedrioa SS: Andrus 3B: McCab OF: Kemp OF: Hamilton OF: McCutchen OF: Melky DH: Hanram SP (12): Lee, Gallardo, Sheilds, CC, Greinke, Vargas, Josh Johnson, Capuano, Cahill, Miley, T. Hudson, Estrada RP (4):Jansen, Pastano, Putz, Papelbon Bench: Ianetta, Doumit, C. Davis, Ichiro, Snider, Thames, Scott, Murphy, Lawrie, Aviles, Crisp, Mayberry, J. Upton, Kubel, AJ Ellis DL: Sandoval, Alex Gonzalez, Brett Anderson, Feftali Feliz, Colby Lewis, Rubby DLR, Minors: d'Arnaud, Rendon, Marte, G. Brown, cuthbert, Segura, Flores, B. Jackson, J. Bell, J. Bradley......C. Martinez, Kelly, Surkamp, T. Walker, Skaggs, Paxton