Patrick Mahomes walked off the field following a loss in the AFC Championship Game last season, and season-ending memories from college and high school crossed his mind.Mahomes had just finished his first season as an NFL starting quarterback destined to become the league’s MVP and capable of taking Kansas City to heights it last experienced a half-century ago, when the Chiefs were winners of Super Bowl IV.His next thought? Get back to the postseason and cross the highest threshold.”When you’re that close, you want to make sure you give yourself an opportunity to get back,” Mahomes said. “We’ve done that this year. We’re in the playoffs. We understand we’re still far away from our ultimate goal.”That process begins Sunday in the divisional round of the AFC playoffs when the Chiefs, coming off a first-round bye, play host to the Houston Texans, a 22-19 overtime winner over Buffalo in the wild-card round.The Chiefs are the only team remaining in the playoffs that reached the divisional round a year ago. They advanced as AFC West champion for the fourth consecutive season, but only after Mahomes overcame injuries to lead a once-battered team to six straight victories.”I loved it,” gushed Kansas City coach Andy Reid, “because the second year (starting) is a tough year for quarterbacks — a tough, tough year.”These guys have great minds in the National Football League who are coaching the defensive side of the ball. They’ve had a whole offseason to study and they’re going to come back with their absolute best against you, and he answered it.”Mahomes’ numbers are not as sparkly as last season, but he’s more tested after overcoming a tender ankle, bruised hand and, most critically, a dislocated kneecap that kept him out just two games.”He didn’t flinch,” Reid said. “He kept the same attitude, the same work ethic, and he went after it. He had a major injury that he pushed through.”Other Chiefs who battled injuries included an assortment of running backs, as well as Mahomes’ blind-side tackle (Eric Fisher) and swiftest receiver (Tyreek Hill). The offense still ranked second in the NFL with a 6.22-yard average per play.Defensively, tackle Chris Jones and end Frank Clark overcame injuries, safety Tyrann Mathieu asserted leadership and first-year coordinator Steve Spagnuolo shaped the group into a fierce unit that is allowing 11.5 points on average during its six-game streak.