"I'm pretty sure, 100 percent sure," Allen said when asked if he would play Sunday. "I'm 100 percent sure ... we'll see what the coaches want to do."
"Feel good," Williams said when asked if he would play. "Yeah, yeah, yeah."
The Chargers listed Allen and Williams as questionable; however, both were full participants in Friday's practice.
The Chargers are 5-4 and on pace to earn their first playoff berth since 2018 as they prepare for a rematch against the AFC West-leading Chiefs (7-2). The Chiefs defeated the Chargers 27-24 in Week 2.
"To get some additions, we've had so much subtraction, to get the addition is important for our team," coach Brandon Staley said.
The Bolts played the past two weeks without both Allen and Williams.
A 10th-year pro, Allen strained his left hamstring in a Week 1 win over the Las Vegas Raiders and reaggravated the injury multiple times, including while training during the Bolts' bye in Week 8.
Since the season opener, Allen has appeared in only one game, playing on a snap count in the first half of a Week 7 37-23 loss to the Seattle Seahawks. The Chargers' leading receiver since 2017, Allen has been limited to six catches for 77 yards this season.
"It sucked, been frustrating," Allen said of missing time. "Just looking to bring back that energy and that play-making ability."
Williams suffered a high-ankle sprain in Week 7 but said Friday that he felt "200 percent" in his recovery.
"Really, just doing everything possible to get back on the field," said Williams, who has 37 receptions for a team-high 495 yards and three touchdowns.