Tebow, who did not play last weekend as his two fractured ribs continue to heal, still is "not ready" to return to the lineup, according to coach Rex Ryan.
Ryan hasn't ruled him out but didn't paint an optimistic picture Thursday.
"I'm still not ready to say I'm comfortable with him (playing) right now," Ryan said. "We'll see how it goes (Thursday)."
Tebow is medically cleared to play, according to the Jets, and he did work "quite a bit more" with the scout team Wednesday than he did the previous week, Ryan said. But the coach, heavily criticized for dressing a banged-up Tebow for a Thanksgiving night game against the New England Patriots, seems hesitant to activate him.
Tebow suffered the injury nearly four weeks ago against the Seattle Seahawks. Initial X-rays were negative, according to the Jets, so he played the following week against the St. Louis Rams. Tebow complained of discomfort, and further diagnostic tests revealed the fractures, the Jets said. Nevertheless, he dressed as the No. 2 quarterback against the Patriots. He did not play, and Ryan later said he "regretted" the decision to keep Tebow active.
The Jets' quarterback situation got complicated last Sunday, when Greg McElroy, No. 2 for the first time in his career, replaced an ineffective Mark Sanchez and rallied the Jets to a 7-6 victory over the Arizona Cardinals.
Sanchez was benched in the third quarter after having thrown three interceptions and for only 97 yards.
On Wednesday, Ryan announced that he would stick with Sanchez as the starter, but he hasn't revealed his plan for No. 2.
Ryan, however, doesn't think his coaching future is tied to how Sanchez is performing.
"Obviously we need to win. This is a big decision," he said. "(A big factor) in determining wins and losses is the play of your quarterback a lot of times. But no, I don't feel that my future's tied in with how we do things (with the quarterback)."
Offensive coordinator Tony Sparano said Sanchez's return from the bench has gone well this week in part because the quarterback isn't pretending that it's business as usual.
"I wouldn't say (he's) the same guy, no," Sparano said Thursday. "I would say he's the kind of guy, he understands what happened. He understands the magnitude of what happened. All that said, does he approach practice differently? No. He's approached practice as a professional every single day he's been in this building."
Ryan said Tebow would be the primary backup if he's "completely healthy," but the coach remained cagey on Thursday.
"I'm not willing to say that just yet," he said of his backup plan. "I still want to go through the week and make that decision."
Tebow wants to play. He said he's well enough to play at a high level against the Jaguars but he also acknowledged that the most recent X-rays, taken last Sunday, showed "some healing, but (there are) still fractures."
"Having Tim on the sideline gives us another weapon and is something that, when you don't have him out there, you lose that part of your game plan," Sparano said.
On Wednesday, Tebow declined to speak with the Jacksonville media on a conference call, perhaps an indication that he already knows he won't play.
Tebow attended high school in the Jacksonville area and became a football icon at the University of Florida in Gainesville. He's a big draw. The Jaguars have sold extra tickets for the game, recently announcing that they opened an extra section in the upper deck to accommodate fans.
Tebow will make the trip with the team even if he does not dress.
"I don't see why not," Ryan said. "Yeah, he'll travel."
Information from ESPNNewYork.com's Jane McManus was used in this report.