Here's what I read on the Bears website:
Part of the issue might be that Horsted, listed at 215 pounds, is the lightest tight end on the Bears roster. Once an oversized 6-4 receiver, he is now adjusting to the realities of his new position.
"You really got to get in it at tight end," said Horsted. "At the wide receiver spot, you're kind of out there. You're dealing with cornerbacks, who you can throw around a little bit as a bigger guy. Now, I'm the smaller guy and getting thrown around if I don't have good technique."
The transition was slowed by a knee injury that has been bothering Horsted since the spring. He finally reached full health last week, just in time for the game against the Colts, and credits the patience of the Bears coaching staff for his recovery.
"It had kind of just been hindering me," said Horsted. "They did a really good job of giving me time to make sure it's fully healed, so it didn't continue to compound. And now I feel good. I feel really good."