The Jets may learn Tuesday whether starting quarterback Sam Darnold is ready to return.

Darnold, who has missed the last three games due to mononucleosis, will undergo tests Tuesday that will determine whether doctors are ready to clear him for Sunday’s game with the Cowboys.

“I feel good. Energy’s awesome,” Darnold said during his weekly appearance on “The Michael Kay Show” on ESPN Radio. “Just looking to play this week, but gotta wait for the doctor’s orders tomorrow. I’m excited to hear the news, I have a feeling it’s going to be good news. I thought maybe it would come last week, but had to wait it out again. Hopefully this week it’s better news and I get to practice and get ready for a game on Sunday.”

The Jets were hopeful Darnold would return last week and he took all the first-team reps on Wednesday and Thursday. Then, the doctors ruled him out on Thursday night.

“I knew there was a chance that I was going to be out,” Darnold said about last week. “I felt good. My energy has been awesome, I’ve been recovering really well. I thought I was on the mend, which I am. That kind of sickness unlike any other where you feel good, but you might not actually be good and ready for contact. It’s unlike anything I’ve ever gone through.”

The Jets started Luke Falk for the second straight game and he threw two interceptions and was sacked nine times.

The Jets’ offensive line is trying to diagnose what keeps going wrong for it. The unit made two changes to the starting lineup Sunday with Alex Lewis at left guard and rookie Chuma Edoga at right tackle. The results were not pretty with the Jets allowing 10 sacks (backup David Fales played the final series in place of Falk.)

“There’s always going to be an adjustment when you throw two new guys in there starting,” Lewis said. “When you look at tape, you’ve got to be your own worst critic as an individual and you’ve got to look at yourself first and realize what you did wrong and what you did right and fix those mistakes. As a unit, you’ve got to look at the communication problems that we had. Those things you’ve got to eliminate right away. You can’t have those if you want to have a successful drive and be able to produce.”

Gase said it was not all on the linemen. There were breakdowns in play-calling, route running and a failure to get the ball out quickly by the quarterback on some of the sacks.

“We all took our turns as far as being part of that sack number. It was not pretty,” Gase said. “It was just a bad performance on the offensive side.”

TE Chris Herndon (violating league’s substance abuse policy after a DUI arrest) and OLB Brandon Copeland (violating league’s performance-enhancing drug policy) are eligible to return to the active roster after serving their respective suspensions. The Jets have a roster exemption this week for both, so they do not need to activate them immediately. Gase said he needs to see them practice before determining whether they have a role this week. … Gase was unsure whether LB C.J. Mosley [groin] can practice Wednesday. Mosley has missed the last three games. … DE Henry Anderson suffered a shoulder injury in Sunday’s loss and is “week-to-week,” according to Gase. It sounds as if Anderson could miss this week’s game. … The Jets signed DL Bronson Kaufusi to the practice squad Monday after waiving him last week. They released LB Jamey Mosley, C.J.’s brother.