The nature of the injury to Mahomes' right ankle was confirmed Sunday by an MRI, which showed no other damage, a source told Schefter.
"It feels better than I thought it was going to be now," Mahomes said after the 27-20 victory that put the Chiefs in the conference title game for the fifth straight season. "Obviously, I have a lot of adrenaline going right now, so we'll see how it feels. But I'll hop right in the treatment and try to do whatever I can to be as close to 100% by next week. Luckily for us, we played the early game on Saturday, so we get an extra almost half a day that I can let that ankle rest."
Chiefs coach Andy Reid noted after Saturday night's game that Mahomes has played through ankle injuries before.
"Let's just see how it goes here the next couple days. It's going to be sore, I know, but let's see where he is at," he said. "He's had this before, and he was able to keep pushing through."
Mahomes injured his ankle in Week 1 of the 2019 season, also against the Jaguars, and didn't miss any time, throwing seven touchdowns and averaging 409 passing yards while leading the Chiefs to victories the next two games, according to ESPN Stats & Information research.
On Saturday, Mahomes injured the ankle late in the first quarter, when he went down awkwardly after completing a pass to reserve tight end Blake Bell. Though the quarterback was obviously favoring the ankle, Mahomes stayed in the game long enough to finish the drive, which ended with a field goal that gave the Chiefs a 10-7 lead.
Mahomes initially resisted the Chiefs' requests that he retreat to the locker room to have the ankle X-rayed, though he eventually relented.
X-rays of the ankle were negative. The Chiefs also had Mahomes do some agility drills.
In Mahomes' absence in the second quarter, backup quarterback Chad Henne led the Chiefs on what proved to be a key drive. The Chiefs drove 98 yards for a touchdown, which came on Henne's 1-yard pass to Travis Kelce.
Mahomes returned for the second half and went 22 of 30 for 195 yards and two touchdowns. He said the tender ankle affected his throwing on certain passes.
ESPN's Adam Teicher contributed to this report.