JACKSONVILLE – Senior writer John Oehser's Thursday notes and observations: Jaguars defensive coordinator Todd Wash on Chiefs Head Coach Andy Reid, Jaguars cornerback Jalen Ramsey on Chiefs quarterback Patrick Mahomes and Wash on Jaguars safety Tashaun Gipson versus Chiefs tight end Travis Kelce …

1.The Chiefs' No. 1-ranked offense presents a slew of physical challenges – Mahomes, running back Kareem Hunt, receiver/returner Tyreek Hill and Kelce among them – but Wash said the mental challenges may be as significant. A primary reason: Reid's scheme presents as many pre-snap looks and in-play misdirection and deception as any offense in the NFL. "They're getting all the recognition for a reason," Wash said. "They're very good offensively. They do a lot of different things to make you go out and really start thinking instead of playing fast. It's important we go out and do what we do, but we have to play fast. They're extremely fast at all positions." The Chiefs against Denver on Monday showed one formation in which four receivers simulated going in motion before the play. "It's unique," Wash said. "Coach Reid does a phenomenal job of making you think defensively. The biggest thing for us is we have to rely on our base fundamentals and play fast."

2.One pre-game focus: the matchup of Gipson and Kelce, widely considered one of the NFL's two or three best receiving tight ends. "Gippy's going to have his hands full with it, but we like the matchup," Wash said. "Both of them are going to be challenged with it and when we come out of the game we're going to see who's the better player." The Jaguars believe strongly in Gipson's ability to negate elite tight ends; linebacker Telvin Smith on Wednesday called him the "Tight End Whisperer," and he was matched up one-on-one extensively in Week 2 with Patriots tight end Rob Gronkowski when the All-Pro managed just two receptions for 15 yards. "You can't measure his heart," Jaguars All-Pro cornerback Jalen Ramsey said when asked about Gipson playing at 5-feet-11, 211 pounds against a tight end such as Kelce (6-5, 260). "You can't measure how much he loves the game and his passion and his confidence. You can't measure that. Size … whatever, that is cool. We have full confidence in Gip and whoever else is going to line up against him."

3.Another pre-game focus: the need for the Jaguars to keep Mahomes in the pocket. "That has been an emphasis this week," Ramsey said. Mahomes has thrown 14 touchdowns with no interceptions in four games, and his 192 yards on completions outside the pocket against Denver Monday were the most by an NFL quarterback in 10 years. "He reminds me a lot of [quarterback] Russell [Wilson] of the Seahawks, how he can get out of the pocket and still launch deep balls and how his receivers work really hard for him when he is scrambling and they are doing plaster," Ramsey said. "They make it tough on DBs (defensive backs) and linebackers and everyone covering – just running all across the field. It is basically a track meet with guys. That makes it tough."

4.Sunday will mark Nathaniel Hackett's second game at Arrowhead Stadium as the Jaguars' offensive coordinator. The first? His first game in the position – a 19-14 Jaguars loss on November 6, 2016. The Jaguars outgained the Chiefs 449-231 that day but committed four turnovers to none for Kansas City. While Hackett had served as the Jaguars' quarterbacks coach since the start of the 2015 season, that was his first game working as coordinator with quarterback Blake Bortles. Watching him in that game and watching him now … to me, it looks like two different people," Hackett said. "I'm excited to continue that growth for him, but it's definitely two different games to compare two years ago to this year." 

5.The Jaguars' injury news was positive Thursday, with guard Andrew Norwell (foot), center Brandon Linder (knee) and tight end Austin Seferian-Jenkins (core muscle) returning to practice after missing Wednesday's practice. The trio worked on a limited basis along with four players who also worked limited Wednesday: running back T.J. Yeldon (ankle), guard A.J. Cann (triceps), right tackle Jermey Parnell (knee) and defensive end Calais Campbell (ankle). Yeldon/Cann/Parnell/Campbell all played through their issues this past Sunday against the New York Jets, and Seferian-Jenkins has been playing through his issue much of the season. Linder has missed practice Wednesdays because of the knee injury and was forced from Sunday's game with back spasms. Running back Leonard Fournette (hamstring) and cornerback D.J. Hayden (toe) have been ruled out for Sunday and did not practice Wednesday or Thursday. …