Cooper, who signed a five-year, $100 million deal to remain with the Cowboys in March, had a career-high 1,189 receiving yards in 2019. Michael Gallup had 1,107 yards as they became the first pair of Dallas wide receivers to post 1,000-yard seasons in the same year since 2006.
Lamb fell to the Cowboys' pick at No. 17 overall after he posted back-to-back 1,000-yard seasons at Oklahoma and was viewed by many as the top receiver in the draft.
"I think it was a great pickup," Cooper said. "You have to draft the best player on the board. Everybody understands that. He's a great receiver. I think with me and Michael Gallup going for 1,000 yards last year, the expectation is to have three 1,000-yard receivers this year."
There have been only five instances in which an NFL team has had three 1,000-yard pass-catchers in a season, with the last coming in 2008 when Larry Fitzgerald, Anquan Boldin and Steve Breaston each went for more than 1,000 yards with the Arizona Cardinals.
Cooper spoke to the media Tuesday for the first time since deciding to remain with the Cowboys despite a larger offer from Washington. His deal with the Cowboys included a $10 million signing bonus and a fully guaranteed $40 million. His $20 million base salary in 2022 will become fully guaranteed if he is on the roster the fifth day of the 2022 league year.
"I just liked everything about being a Dallas Cowboy. Just the atmosphere both in the building and outside the building in terms of the city of Dallas and surrounding areas," said Cooper, who was acquired in a 2018 trade from the Raiders. "I guess that would be the same reason why I was willing to take less money to stay here. That coupled with the fact that I've been privileged to play on different teams, so I understand the culture isn't the same in every city. Every team isn't the same ... Me being able to see that on another team and having the opportunity to be on a team I really love, I wouldn't trade that for a little bit more money."
Despite no official offseason program, Cooper said he does not feel behind in his preparation for the 2020 season. The Cowboys are only on the second day of on-field conditioning since players reported to The Star last week. The first padded practice is not until Aug. 17.
Cooper said he has some "machines" at his house that helped keep him in shape, and he bought a gym membership.
He also said he and quarterback Dak Prescott with other receivers, tight ends and running backs worked out together, including some at a football field Prescott built in his backyard.
"We've all been getting together pretty consistently for months now," Cooper said. "Working on route-running, working on the offense and everything like that. We've been getting a lot of work in, getting that timing right as if we were in minicamp or OTAs."
In the workouts, Lamb impressed Cooper.
"I think he's a quick learner," Cooper said. "He already has a good foundation. He's fundamentally sound in his route-running. It's very small, nitpicky things that I help him with that I may see with him being a rookie, but I think he has a really good foundation."