"They need to maximize [their earnings], because they can't do this for the next 40 years. They have a short amount of window. They're trying to get what they can."
Kelly says he understands why his leading wide receiver, DeSean Jackson, wants more money. And he says he understands why his All-Pro guard, Evan Mathis, also wants a new deal.
What Kelly says he won't tolerate from any of his players, however, is bringing their contract problems to work with them.
"At the end of the day, when you come to work, if anything is a distraction to you, then you're not being the best player you can be," he said.
"What you can control is how you show up every single day, what your attitude is when you're in the meeting rooms, what your attitude is when you're on the practice field, and what your attitude is when you're in the weight room."
League sources confirmed an NFL Network report that the Eagles put Mathis, 32, on the trading block with Jackson last month after his agent, Drew Rosenhaus, approached them about renegotiating the 5-year, $25 million contract Mathis signed in March 2012.
Rosenhaus declined to comment yesterday, and, astonishingly, Kelly claimed to be ignorant of both Mathis' unhappiness with his contract and the fact that the Eagles were accepting trade offers for him.
Your starting left guard has a "For Sale" sign around his neck and the $6.5 million-a-year coach, who works two office doors down from the general manager, Howie Roseman, knows nothing about it? OK, if you say so.
A source close to the situation said the idea to put Mathis on the trading block was the Eagles', not the player's.
It's very unlikely Mathis is going anywhere, though. According to a league source, the Eagles want at least a third-round pick for him. Despite his being a first-team All-Pro selection this year, that's a steep price for an interior lineman who will turn 33 in November, even if Mathis is playing the best football of his life.
After spending the first 6 years of his career as mostly a backup with three teams, Mathis was an under-the-radar signing by the Eagles in 2011, overshadowed by the arrival of Nnamdi Asomugha, Vince Young, Ronnie Brown, Dominique Rodgers-Cromartie and the rest of the infamous Dream Team free-agency class. But he blossomed under the tutorship of former offensive-line coach Howard Mudd and has started 47 of 48 games the last three seasons.
The athletic 6-5, 305-pound Mathis played every offensive snap last season and all but three the year before. He's allowed only three sacks the last 2 years and was a first-team All-Pro selection this season. Pro Football Focus ranked him as the best offensive lineman - inside or outside - in the NFL last season.
Mathis' current 5-year deal is worth $25 million, but has incentives and escalators that could raise it closer to $30 million. He is scheduled to earn $5.15 million this season and $5.6 million next year.
The Eagles' five starting offensive linemen count $25.6 million against the team's $133 million salary cap. Mathis' $6 million cap cost this year is second only to left tackle Jason Peters ($8.3 million) among the five starters.
Asked whether he worries about players dragging their contract problems onto the field and into the locker room with them, Kelly said, "generally, maybe." But he said he had no such conerns about that happening with Mathis.
"You talk about a go-to-work, lunch-pail mentality [guy], that's Evan Mathis," he said. "I don't worry about Evan from that standpoint.
"Since Day 1 when I got here, Evan has been just outstanding. Whether it's in the meeting rooms or in the weight room or on the practice field, he practices every day. He may have played the most snaps in the NFL last year. I know DeMeco [Ryans] did on defense. But Evan also played 79 snaps on extra points. I'm not worried about him."
Maybe he should. While it's hard to believe Mathis would ever let his contract unhappiness affect him the way it did Jackson back in 2011 when the Eagles wouldn't give him a contract extension, a source close to Mathis said the offensive lineman is considering skipping some or all of the voluntary OTAs this spring if he doesn't get a new deal.
Kelly said Mathis talked with him since the season ended, but "never said anything to me" about his unhappiness with his contract.
That's not surprising, since Kelly has nothing to do with contract negotiations, which is why he can say he hopes every one of his players gets paid a billion dollars.
"I don't deal with numbers," he said. "That's not my job. My decisions are all [about] where the guys fit schemewise.
"I don't look at it and say, 'I denote that guy to make that much money. And this guy should make this much money.' That doesn't fall under my domain.
"I'd love to keep everybody. I've love everybody to be the highest-paid guy at their position in the league. But the reality is it doesn't work that way. You can't say, 'I want a $20 million safety, I want a $20 million linebacker.' That money runs out at some point in time."
On Twitter: @Pdomo