A week after a wealthy doctor pal of Sen. Robert Menendez received an $8.9 million Medicare bill, the Garden State lawmaker sent an e-mail to his chief of staff saying they needed to figure out “who has the best juice” to help with the billing dispute.

Menendez sent the e-mail on Aug. 12, 2009, to Daniel O’Brien after Dr. Salomon Melgen of Florida received the bill for allegedly overcharging Medicare.

“Dr. Melgen is still in the nonlitigant stage, so we should determine who has the best juice at CMS [Center for Medicare/Medicaid Services] and Dept of Health,” a prosecutor read to jurors in Newark federal court Tuesday.

Melgen, who was convicted of Medicare fraud, is on trial with Menendez for allegedly bribing the Democrat for favors in exchange for all-expense-paid vacations, trips on his private jet and campaign contributions.