"You can see so much on film, but when you're out there with them you can see how they process, and Nick can really process," Musgrave said yesterday afternoon at the Nova-Care Complex.
"We know he's a gifted athlete. He can throw the ball exactly where he wants to. He can add air, add touch. He can add velocity and really drive it when it's needed. But to see the way that he can visualize formations, coverages, and process what he sees has been impressive."
In terms of areas in which he thinks Foles can continue to improve, Musgrave noted a few. Among them: Getting rid of the ball quicker, taking fewer hits and continuing to at times move the ball forward with his legs.
Each repetition in the spring is graded and, according to his position coach, Foles is his own worst critic, even after tossing 27 touchdowns to only two interceptions last season.
"We want him to be smart late in the down, both with the football and also with his body," said Musgrave, who was speaking to reporters for the first time since joining Chip Kelly's staff. "We try to grade each and every play so they get feedback and then he can also critique himself and know what he can do better."
Replacing Bill Lazor, whom the Dolphins hired to run their offense, Musgrave, 46, joined the Eagles after three seasons as the offensive coordinator in Minnesota under Leslie Frazier, who along with his staff was fired in late December after a disappointing five-win season.
Musgrave, a former Oregon quarterback who as a pro backed up Joe Montana, Steve Young and John Elway, has coached for seven NFL teams and the University of Virginia. This is actually his second stop in Philadelphia.
At the start of the 1998 season, Musgrave served as an Eagles' offensive assistant. But after six games, when then-head coach Ray Rhodes demoted offensive coordinator Dana Bible, Musgrave, then only 30 years old, was tasked with calling the plays. After that season, during which the Eagles won only three games, Rhodes and his staff were fired, paving the way for the start of Andy Reid's tenure.
"I pride myself on being a lifelong learner, and that kind of means walking off the practice field or the game field every day and learning something that I didn't know before," Musgrave said. "I brought a lot more experience now than I did at that time and I'm a long ways from knowing it all, that's for sure. Still enjoying it. I know that."
When Musgrave arrived back in Philadelphia this year, he was greeted by a couple of familiar faces: running-backs coach Duce Staley and offensive assistant Tra Thomas both were young players on that 1998 squad.
"It's awesome to have him here, knowing the relationship we had," said Staley, who calls his coach-turned-colleague "Musgravey."
"He's adapted quite well. The funny thing about it was, as soon as he walked in the door you could tell he was on top of his game."
Eagles offensive coordinator Pat Shurmur, the Cleveland head coach from 2011-12, said he had tried to hire Musgrave as his coordinator with the Browns.
"I've known Bill a long time," Shurmur said. "I feel philosophically we're very similar in what we want to tell the quarterback, which has made it a very easy transition for Bill to pick up where we are in Year 2. It's been good. It's been very smooth. No matter who says something to the quarterback, we're all on the same page, and I think that's most important."
Musgrave met Kelly years ago at Oregon during a workout for former Ducks quarterback Dennis Dixon. At that point, Kelly had recently arrived in Eugene from New Hampshire. Musgrave, like everyone else around football, followed the coach's ascent in the years that followed.
"It's been very interesting to learn the intricacies of the system," Musgrave said. "I'm far from mastering it at this stage, but I'm learning a bunch each and every day. I've really enjoyed watching it grow over the years.
"It's a system that thinks players first, then plays, which is brilliant. It doesn't mean that we're always going to run a certain play just because it's worked in the past, but we're going to take the strength of our players and customize, tailor the system to fit them."
On Twitter: @jakemkaplan