Trevone Boykin is not walking through that door. Josh Doctson is not walking through that door.

Gary Patterson doesn’t have to say it. He doesn’t have to have all the answers right now, either. But he does need his TCU players to start figuring how to win without them.

“It doesn’t matter who you lose -- you’ve got to turn the page and the next guy has to grow up,” Patterson told reporters last week. “You’ve got to put your back against the wall and keep climbing the ladder. So we’ll see how we do.”

The dangerous unit co-offensive coordinators Doug Meacham and Sonny Cumbie constructed around those departed game-changers helped win 23 games in two years. This offseason, they're facing the challenge of reloading and replicating that success.

Of TCU's significant losses on offense, coach Gary Patterson said, "It doesn't matter who you lose -- you've got to turn the page." AP Photo/Orlin Wagner

Boykin, Doctson and fellow veterans Aaron Green and Kolby Listenbee combined for more than 15,000 total yards of offense over their two seasons with Meacham and Cumbie. All four should be NFL draft picks next month. The offensive line will feature new faces this fall too.

The expectations for this offense in 2016, then, aren’t easy to judge at the moment. Patterson isn’t tipping his hand much on the quarterback decision, other than suggesting he won’t name a winner in the Kenny Hill vs. Foster Sawyer battle this spring.

“It’s a day-to-day thing,” Patterson said last week. “Saturday wasn’t good for them. Then the Tuesday scrimmage was better for them. But, you know, you can tell every day we keep getting better.”

Freshman Isaiah Graham and LSU transfer John Diarse have brought a spark to the wide receiver room in their first few months in the program. The competition at running back and along the line will continue. Even when all the starters do get figured out, we won’t know much until September.

But we at least have some evidence -- a small sample size, but it’s something -- of life without Boykin and Doctson. Their late-season injuries as seniors forced Patterson and the Frogs to plug in backups and try to make it work.

The results? When Boykin was available last season, TCU averaged 44.7 points per game, 7 yards per play, 9.1 yards per passing attempt and scored on 46 percent of its offensive drives.

When he wasn’t -- injured for the Kansas and Oklahoma games, suspended for the Alamo Bowl -- the Frogs’ production dropped to 32.4 points per game, 5.8 yards per play and 7.4 per attempt. They managed to score on 35 percent of their drives. Half their drives ended in punts or turnovers.

Doctson got hurt with essentially 4 1/2 games left in the season. When he wasn’t an option, TCU quarterbacks combined to complete 57 percent of their passes.

Throughout the challenging weeks without them, Patterson reminded reporters (and, presumably, his players) that TCU was about to lose those seniors anyway. Life without Boykin and Doctson began a bit earlier than planned. Confronting it in November, instead of waiting for this spring, ought to prove valuable for the growth of their successors.

What Meacham and Cumbie do with all these new parts probably will determine whether the Frogs become a top-25 squad and Big 12 title contender once again in 2016. Boykin and Doctson were once-in-a-long-time type stars for the Horned Frogs. Now they just need a few more.