ST. JOSEPH, Mo. (AP) — Alex Smith did everything the Kansas City Chiefs asked of him last season.Now, he must do more.The veteran quarterback with a reputation for being a game manager is being called upon to build on a solid if unremarkable season.After signing a four-year, $68 million extension before training camp, Smith proceeded to throw for more than 3,000 yards and 18 touchdowns with only six interceptions, despite having his season cut a game short by injury.But if the Chiefs hope to return to the playoffs — and win their first postseason game since 1993 — it will almost certainly be because their passing game flourishes this season.“I feel really good,” said Smith, who is entering his 10th season in the league. “It’s a point of emphasis for us all offseason. We worked hard on it, QBs and wideouts included.