ENGLEWOOD, Colo. -- A star was born among the Broncos' tight ends last year, and now the team knows it must take steps to ensure that Julius Thomas remains with the team for his prime, shining years before the supernova stage.

That is why, at the NFL Scouting Combine in Februrary, Executive Vice President of Football Operations/General Manager John Elway mentioned the contract status of "both Thomases" when he mentioned why Eric Decker would be allowed to test the market.

Like wide receiver Demaryius Thomas, Julius Thomas' first NFL contract is up after this year, and if he has another season like the one in which he set a Broncos record for touchdown receptions by a tight end, he will command a hefty price.

The Broncos' patience in Thomas paid handsome dividends, and was crucial in elevating the offense from explosive in 2012 to record-breaking a year later. His ankle troubles of 2011 and 2012 were behind him, and the practice work he'd received helped provide needed polish, given his limited playing experience in high school and college.

"Times have been tough but my coaches -- I've really got to compliment them for just always staying on top of me, making sure I'm learning, taking that extra time to help me pick up on new things," Thomas said in January. "It's all a learning experience. I love it."

The next step for Thomas will be to improve as a blocker. That was always going to be the most rigorous aspect of his transition from college basketball forward to NFL tight end; it's the least natural aspect that process.

But there is reason to believe he can become a capable blocker, and that rests in his physical presence and his diligence. His receiving skills likely ensure he'll never be primarily a blocker, but with a bit of improvement, he'll be the all-around threat the Broncos envisioned.

Quarterback Peyton Manning noticed Thomas' work ethic last year.

"He has just bought in," Manning said in January. "He has committed himself every day to learning from his tight ends coach (Clancy Barone), learning from (Offensive Coordinator) Adam (Gase) to talking to me about things he wants to work on. I always like that, being an older player, when a young player truly wants to be a great player. I think he does. If he keeps that up, he will be for a long time."

Thomas was only half of the Broncos' tight end haul in the 2011 draft; later in the third day, they added Virgil Green, who was Thomas' primary backup last year. Green is more polished as a blocker, and was frequently used in two-tight end sets. His knowledge of the offense and his versatility -- he lined up at running back briefly in the AFC Championship Game -- are assets.

But from Thomas to Green and beyond, tight end could endure a transition in the next 12 months. All four tight ends still on the team from last season have contracts that expire after the 2014 season. Joel Dreessen, a free-agent signee in 2012, didn't play at all in the postseason, and fellow 2012 pickup Jacob Tamme saw a reduction in offensive repetitions from that season.

But Tamme proved to be a vital inside option when injuries struck and had one of the best games of his career at New England last Nov. 24, running precise routes and making catches in heavy traffic. Tamme was also one of the Broncos' best special teamers last year.

Offseason signees Jameson Konz and Cameron Morrah currently help round out the group, but the wild card in the bunch is practice-squad veteran Gerell Robinson, who was converted from wide receiver during the season and worked at tight end throughout the year after being released at the final preseason cutdown and brought back to the practice squad a day later.

Listed at 6-foot-4 and 220 pounds as a wide receiver, Robinson displayed good hands and ran precise routes, but didn't have the speed to gain consistent separation on the outside, which led to him sliding out of the 2012 draft despite a prolific career at Arizona State. With some bulking up, tight end offers Robinson the chance to make more plays in traffic, and get mismatches against smaller cornerbacks and slower linebackers.

But flourishing on the practice field is one thing; doing it in the games -- or even in full-contact preseason practices -- is another matter. His progress will bear close monitoring this summer. Ideally, he would blossom and become a valuable insurance policy behind Thomas, but a position shift creates a steep learning curve that Robinson must overcome.