The toughest cut for the Chicago Bears and other NFL teams won't be made until Sept. 2, but after three weeks it's apparent possibly the most difficult one for Bears coaches will involve the tight end/fullback situation.

Coaches have loved fullback Tyler Clutts' toughness since he arrived as a veteran of the CFL and Arena League. Nothing has changed, whether he lines up in front of Matt Forte or Michael Bush or is helping on special teams.

However, the modern state of football always has fullbacks on alert when there are coaching or offensive changes. Fewer teams than ever are using a traditional fullback, and when the Bears switched to Mike Tice as offensive coordinator it was uncertain how much Clutts could play or if they even would keep a fullback.

"I knew that it would be an uphill battle for me," he said. "It's just my job not to worry about the things I can't control. On the field, I just have to show that I can do what the other positions can't."

The Bears don't know for certain if they have a sledge hammer among their tight ends to help Forte or Bush from the blocking position in the backfield on short yardage. If they don't, they can always keep Clutts. However, the big threat to Clutts' job security comes from tight end Kyle Adams, who has shown an ability to be the "H-back" and also to be a tight end on the line.

Each day Clutts is one of the last off the practice field and frequently can be seen hammering the one-man sled by himself after everyone else has left the field.

When the Bears staged a rare defensive back pass rush drill one day last week with backs picking up blitzers, the best at picking up the DBs was Clutts. And it wasn't even close.

"You don't know what will happen," Clutts said. "(Former Bears' offensive coordinator) Mike Martz wasn't a big fullback guy last year but we ended up using a lot of fullback. It's just a matter of me making my presence known and felt."

Martz had orginally wanted a tight end as a blocking back for short yardage, but Brandon Manumaleuna failed miserably. Clutts blocking in short yardage became a much better option last year.

The special teams aspect of Clutts' job is huge, but special teams coordinator Dave Toub also regards Adams as one of his better special teams players.

It's hard to see rookie fourth-round pick Evan Rodriguez being cut while he learns the tight end and H-back spots -- especially with the good hands he's shown in camp. So the choice could wind up being to keep four tight ends over three tight ends and a fullback.

"It just comes down to who can make themselves most valuable to the team," Clutts said.

Follow Bears reporter Gene Chamberlain on Twitter @CBSSportsNFLCHI.