Lester, Votto, Upton, Blockbuster in keeper league

[I Heart Chase]

What up guys. I am in a 12 team keeper league where you can keep 5 players at the end of each season drafted in rounds 1-18 along with an additional 5 players drafted in rounds 18-24, which are called Bonus Keepers. I have been offered Justin Upton, Lance Berkman, and Daisuke Matsuzaka for Jon Lester and Joey Votto. Should I do it? I believe Upton has perennial MVP candidate type potential, and a future centered around Heyward and Upton could allow me to be among the elite in my league for years to come. However, Berkman and Dice K are big question marks. I wonder if this trade actually hurts me this year, even if it helps me in the future. That is an issue because I believe I am a contender this year. Furthermore, Votto and Lester will be studs in the future as well and would be two of the players I choose to keep for next year if I don't trade them. Thanks in advance, and I would be glad to offer my advice on any trades that people link onto their response to my post. My roster is as follows:

1B: Joey Votto
2B: Kelly Johnson
SS: Ryan Theriot
3B: Alex Rodriguez
OF: Nelson Cruz
OF: Jason Heyward
OF: Shane Victorino
Util: Bobby Abreu
Bench: Scott Podsednik
Bench: Kyle Blanks
Bench: Matt LaPorta (Bonus Keeper)
Bench: Michael Stanton (Bonus Keeper)
DL: Brian Roberts
DL: Asdrubal Cabrera

SP: Adam Wainwright
SP: Jon Lester
SP: Cliff Lee
SP: Ricky Romero
SP: Gio Gonzalez
SP: Randy Wolf
SP: Scott Olsen
SP: Aroldis Chapman (Bonus Keeper)
RP: Joakim Soria
RP: Neftali Feliz
RP: Hong Chi Kuo (we do holds)
RP: Arthur Rhodes
DL: Huston Street

[I Heart Chase]

I forgot to add some additional background information:

League type: Head to Head
Categories: Hitting - R, HR, RBI, AVG, OBP, TB, SB Pitching - W, L, SV, HLD, K, ERA, WHIP

[I Heart Chase]

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