Reid and general manager Brett Veach watched some recent videotape of McCoy's play, and that was enough.
"There are not a lot of 31-year-old running backs running around out there,'' Reid said. "But he still has the great feet and the vision.''
McCoy had the least productive season of his 10-year NFL career in 2018 for the Buffalo Bills, rushing for 514 yards and scoring three touchdowns. But in Kansas City he will be reunited with Reid, whom he played under for four successful seasons with the Philadelphia Eagles.
McCoy agreed with Reid, saying that losing three starting offensive linemen and going through four starting quarterbacks, including rookie Josh Allen, made things difficult for himself and the Buffalo offense.
"[The Bills lost] three Pro Bowlers on the line, and we had guys kind of filling in at the last minute,'' McCoy said. "Give them credit. They did [well] to the best of their abilities. We had a young quarterback and a lot of [times] he was coming in and out of games with injuries and different things like that . . . That was a tough year. Mentally, physically, it was definitely tough.''
McCoy said he picked the Chiefs over other offers, most notably one from the Los Angeles Chargers, so he could reunite with Reid.
"The best part about it is Andy Reid,'' McCoy said. "There are so many different answers [why]. I love coach Reid. The biggest thing for me is he's always been honest since day one. He shoots you straight. His family is the same way. As a coach, I've learned so much from him. Now coming here, I'm sure he'll teach me different things. I'm an older player, and I want to stretch my career out as long as possible. I want to be productive as well. I think just playing with him ... when you watch tape of the offense and how they go up and down the field, small plays to big shots, to utilizing all the open space for his players, when you see that, you fall in love with that."
"He knows what to expect,'' Reid said of McCoy. "I've been very honest with him about Damien and how good of a football player he is. I think it's a great situation for both of them and for the team. For where he's at in his career, you're talking about potentially a future Hall of Famer with the numbers and stats he's put together here. Here he has an opportunity to come to what potentially is a good football team as we go forward and be a part of that.''
Reid said the Chiefs plan to have McCoy available against the Jaguars.
"We'll see what he can pick up in a short period of time here, how comfortable he is with it, and then we'll go from there,'' Reid said. "He's a pretty sharp kid so I think we'll be OK. He's been practicing and playing in these preseason games so the conditioning part is not an issue. It's just becoming familiar with the protections and the run game part.
"This is different than what we did in Philadelphia. There will be some familiar things, but it's quite a bit different. He's going to have to get in and learn [the offense] and then we'll just see how that goes. They both have an opportunity to play. I'm not going to put him out there in a bad situation without knowing the plays. I would never do that.''
McCoy said, "I should be fine. I'm a smart dude. I have nothing else to do [other than learning the playbook]. It will be like homework.''
Williams was set to be the Chiefs' main featured back until the McCoy signing. Now the Chiefs plan to go with more of a committee that includes rookie Darwin Thompson. McCoy said he was fine with sharing the backfield, if that's what the Chiefs decide to do.
"Those are some pretty good backs,'' McCoy said. "That's for Coach Reid to [decide]. The good thing about that is he's been doing that for a number of years with different guys like Duce Staley and [Brian] Westbrook, who had really good careers. I'm open to working hard and competing. The ultimate goal is to win. That's one thing I haven't done yet. I've had good numbers. I've done good things. But I want to win. I need to be with a winning team, and whatever it takes to get that done, we'll do."