When there's a trade in any sport, there are questions. How did it come about? What were the teams trying to accomplish?

On Friday, the Rams were involved in their third high-profile trade of the last three years, acquiring wide receiver Sammy Watkins and a 2018 sixth-round pick from the Bills in exchange for cornerback E.J. Gaines and a 2018 second-round selection. The former No. 4 overall pick in the 2014 draft, Watkins immediately brings size, speed, and big-play ability to Los Angeles.

"With Sammy, I think clearly you're getting a special receiver," Rams head coach Sean McVay said. "Obviously, his career when he's been available, he's been outstanding in terms of being able to stretch the field vertically, but when the balls in his hands, good things happen. We feel like he's going to be a good addition to our offense."

With Watkins' proven ability to be a downfield threat — he finished No. 3 with seven receptions of at least 40 yards in 2015 — McVay and general manager Les Snead both said the wideout compliments the Rams' current personnel well.

"When you attack a team with your pass game, you'd like to use the width of the field and the length of the field. And that's what speed can do to allow you to attack vertically as well as the width," Snead said. "So it's really just trying to open the field up. And it's not just one person — it might be a tight end this week. It might be a slot receiver this down. It may be a running back out of the backfield or running the ball. So I think it really helps."

"I feel like adding Sammy to the mix with guys like Robert Woods and Tavon Austin — you're looking at the emergence of Cooper Kupp. Pharoh Cooper's done a nice job, done some nice things, done a nice job filling in. And then the tight ends continue to do a nice job as far as developing in their roles. And obviously we know what a special back Todd Gurley is," McVay said.

While the trade wasn't done until Friday morning, Snead said the two teams have been discussing it for a while. The general manager said talks began in the spring, around the time Buffalo declined to exercise Watkins' fifth-year option. And then when Brandon Beane was named the Bills' general manager after the draft, the conversations started once again.

"We kept talking during the summer and it came to fruition this week," Snead said.

"But, anytime you're able to acquire a player of Sammy's caliber," McVay added, "that was certainly something that we wanted to be able to do and we feel fortunate that we got that done."

While he averaged 62 receptions for 1,014 yards and eight touchdowns in his each of his first two seasons, Watkins' production dipped in 2016 when he missed eight games due to a foot injury. The wideout underwent offseason surgery to correct the issue, and through the offseason program, training camp, and a preseason game, Watkins has been healthy.

In Buffalo's matchup with Minnesota on Thursday, Watkins caught four passes for 39 yards on five targets. Snead said the Rams looked into the wide receiver's health and were satisfied with what they discovered.

"We definitely discussed it," Snead said. "I think it's probably one of the reasons that maybe they didn't put the fifth-year option on him. But when we dove into it, we felt comfortable taking the risk, making this move, and going forward."

Because the Bills declined to exercise Watkins' option, he is now in the final year of his rookie contract. Though Snead said the Rams and Watkins have not yet discussed a potential contract extension out of respect for the player, Snead added Los Angeles doesn't see this trade as a short-term decision.

"I think he's 24, so you don't just do it for the now — although we do think he'll help the now," Snead said. "But because of the age, you'd like for it to be [for the] future as well — long term instead of just short term."

So how will the Rams integrate Watkins into their offense? McVay said the first step will be to figure out where his best position is in the offensive scheme.

"I think that you can't find enough spots for good football players and that's what we're getting in Sammy Watkins," McVay said. "That's our job as coaches, is to do a good job of putting these guys in good situations, finding a way to develop an offense that's conducive for our players skillsets. When you add a player like that, those are the types of players that make coaches look good because he's been so successful throughout the course of his career."

Watkins is currently slated to arrive in L.A. on Saturday. While he won't suit up for the Rams' matchup with the Cowboys, McVay said the team will get Watkins up to speed as soon as possible.

"We'll get him going right away, start getting him acclimated to our verbiage and our system and looking forward to being able to get to know him a little bit better and see how he's able to absorb the material," McVay said. "He's certainly going to be a good addition for our offense and I think the guys are excited about it."