In so many words, he said he hoped Lacy wouldn't revert to his old habits during the break before training camp.
It appears Lacy listened.
According to a source, the Packers running back reunited this summer with trainer Tony Horton, the P90X founder who worked out Lacy shortly after last season after McCarthy gave him an ultimatum to lose weight.
Last month, McCarthy said he hoped Lacy "goes with the plan that he used this year as opposed to last year" when asked about Lacy's summer workout plans. Lacy spent two months with Horton in both Jackson Hole, Wyoming, and in Los Angeles after McCarthy said the running back "cannot play at the weight he was at [last] year."
Horton put Lacy through a variety of workouts, including plyometrics, yoga, cardio, basketball and boxing.
Following those workouts, Lacy returned to Green Bay in April for the offseason program and was 15 to 18 pounds lighter, a source said at the time. However, McCarthy indicated that Lacy's work might not be done.
"Eddie will be fine," McCarthy said in May. "I believe he'll hit the target that we're all looking for when the lights come on."
Horton previously told ESPN.com that he would like to continue to work with Lacy once the Packers' offseason program ended in June but at the time it was unclear whether his schedule would allow it.
"Ideally, what I'd like to do -- he'd have to be in LA for it to work -- but I'd like to see him play [basketball] one day, [go to] boxing class one day and I could work with him for three as opposed to six or seven like before," Horton said at the time. "It would give him more freedom, and the beautiful thing is he wouldn't have to relearn everything again. I would really love the plyometric day and the cardio was essential for him."