But in this case, they have a good excuse and the coach knows there's nothing he can do about it.
Just like last year, when Davante Adams and Khyri Thornton were gone in late May, Montgomery and Hundley will be in Los Angeles from Thursday through Sunday for the NFL Players Association's Rookie Premier event.
"My understanding is the rookie premiere is part of the CBA contract, and I won't touch that with a long telephone pole," McCarthy said last year when addressing the absence of Adams and Thornton. "That's part of the legal counsel. I have no opinion on that stuff. Do I like that they're missing practice? No, I don't like that they're missing practice. I don't understand it either, but that's part of a contract."
The Packers begin OTAs on Wednesday. Thursday's session is the first open to the public (weather permitting) and media.
OTAs are voluntary, but McCarthy believes strongly that offseason workouts play a significant role in preparation for the season. Montgomery, a third-round pick from Stanford, is expected to compete for the No. 3 or No. 4 receiver spot. Hundley, a fifth-round pick from UCLA, likely will be the team's No. 3 quarterback this season.
The rookie event is run by the marketing and licensing arm of the NFL Players Association. Among the guest speakers are former and current NFL players, NFLPA head DeMaurice Smith and NFL Players Inc. president Ahmad Nassar. More than 40 rookies from the 2015 NFL draft class are scheduled to participate. The full list can be found here.