But it turns out, he did the unthinkable a month ago.
He rooted for the Eagles.
"As much as we have the rivalry that we have, and as frustrating as it was for the Cowboys not to be playing, as much as all of that, I was proud of them, given that narrow set of circumstances, could root for them," Jones said last week to the Fort Worth Star-Telegram. "That takes it right down to just absolutely no choice, you either do or you die. And I want to go again."
Like the Eagles in 2017, the Cowboys were the No. 1 seed in the 2016 NFC playoffs, but they were bounced in the divisional round. The Cowboys followed up their 13-3 season with a disappointing 9-7 mark.
Jones said the Eagles' Super Bowl victory has put more pressure on the Cowboys, who haven't won a Super Bowl since 1995 and haven't made it past the divisional round since then.
During the 2017 season, the Cowboys eventually ended up losing Ezekiel Elliott during his six-game suspension that hung over the team all year, and they had middle linebacker Sean Lee for just 11 games. The Eagles, of course, lost their starting quarterback, left tackle, middle linebacker, running back, special teams ace and kicker.
"So just the fact that they did it the way they did it, really for me it sure eliminates one of the real excuses," Jones said. "You can say that you just can’t have the kind of depth, but they didn’t have necessarily that kind of depth but they had enough that they shifted some of the ability of the team to execute their parts where they had their regulars, and we didn’t do that."