Sam Darnold is entering Week 5 with optimism, but his status remains uncertain.

The Jets quarterback is set to have an ultrasound on his spleen and blood tests dones Friday that will determine whether he'll be able to play Sunday against the Eagles.

Darnold had not lifted, run or thrown since being diagnosed with mononucleosis last month, but ramped up his workouts this week after being cleared for non-contact drills Monday, offering hope that he could make his return on time.

"It's a tough thing because you want to s

tay safe," Darnold told reporters Thursday. "I want to make sure that I'm safe out there and that I'm not gonna die. ... For me, sitting back and watching the team play and not having anything to do with the win or the loss, it's not a good feeling for me."

Darnold, selected by New York with the No. 3 pick in the 2018 draft, has been out since Sept. 12 with mono. The Jets had hoped he would be healthy enough to return after the team's Week 4 bye, but will have to wait a little longer for a definitive answer.

"I like our odds better than what they've been," Jets coach Adam Gase told reporters before practice. "Last week, if we would've been playing again, I would've said it's very low. I like the fact that things have looked and progressed in the right direction. But I don't know what that 5 percent is. There's some gray still there."

If Darnold isn't ready, Luke Falk will get the start again. In two games, Falk has gone 32 of 47 for 296 yards and one interception. He’s also been sacked seven times.

The Jets (0-4) travel to face the Eagles (2-2) Sunday, with kickoff set for 1 p.m. ET.