FAYETTEVILLE — The Arkansas defense got good news last winter when defensive end Trey Flowers announced he’d return to the Razorbacks for his senior season.

FAYETTEVILLE — The Arkansas defense got good news last winter when defensive end Trey Flowers announced he’d return to the Razorbacks for his senior season.

The Razorbacks won’t have the same good fortune this year.

Defensive tackle Darius Philon announced he’ll enter the 2015 NFL Draft with an Instagram post Tuesday. Philon, a redshirt sophomore, had been weighing his options after collecting 46 tackles, 11 1/2 tackles for losses and 4 1/2 sacks in 2014.

"I want to say I have had a great journey here in the state of Arkansas," Philon wrote on Instagram. "I feel that I have matured enough to pursue my dreams on to the next level. I know there will be some obstacles that I will have to endure but I feel the University of Arkansas has prepared me well.

"With such excellent coaches, phenomenal players, and dedicated fans, I know this football program will have a very bright future ahead. Please know that wherever I go and whatever I do in life … I will ALWAYS represent the University of Arkansas."

Philon — who earned second-team All-SEC honors last month — is draft eligible because he has completed three years at Arkansas.

The two-year starter played a big role in helping the Hogs complete an impressive turnaround under first-year defensive coordinator Robb Smith last season. Arkansas had back-to-back shutouts against LSU and Ole Miss, allowed 28 points in its final four games and finished 10th in the NCAA in scoring and total defense.

Arkansas coach Bret Bielema visited with Philon in his hometown of Mobile, Ala., earlier this month to discuss his options for 2015. He hoped Philon would return for his junior season and serve as the anchor for Arkansas’ defensive line. Bielema also viewed Philon as a potential leader for a unit trying to replace influential veterans like Flowers, linebacker Martrell Spaight and safety Alan Turner.

"I hope it will be Darius Philon," Bielema said last week. "I think he grew a lot this year and can put himself in the right position if he comes back. He’s that guy."

But Bielema also acknowledged last week that Philon would have "an incredible future in front of him" whenever he decided to begin his pro career.

"We are disappointed that Darius will not longer be part of our football program, but very excited about the opportunities ahead of him," Bielema said in a statement Tuesday night. "It was a privilege to get to know Darius and his family over the past two years. He is a very young and blessed athlete and we wish him nothing but success in life’s path he has chosen."

His departure does leave Arkansas with another hole to fill on its defensive line.

Defensive end JaMichael Winston and nose guard Taiwan Johnson are returning starters, but Philon and Flowers anchored the group by combining for 27 tackles for losses and 10 1/2 sacks last season. The Razorbacks will need more production in the middle from players like Bijhon Jackson, who worked in reserve role.

Arkansas does have three more defensive linemen on campus as early enrollees this semester. Daytrieon Dean, Hjalte Froholdt and Jeremiah Ledbetter are scheduled to participate in spring practice as the Razorbacks prepare for the 2015 season.

Philon becomes the first Arkansas player under Bielema to leave the Razorbacks early to enter the NFL Draft. He’s also the first Arkansas player to do so since the 2013 season, when running back Knile Davis left after his junior season. The Kansas City Chiefs selected Davis in the third round of the 2013 NFL Draft.

Two other Razorbacks who considered an early entry into the draft — running back Jonathan Williams and wide receiver Keon Hatcher — have decided to return to Arkansas. Underclassmen have until Thursday to declare for the 2015 NFL Draft.

Chaney’s Departure

Bielema also offered his first public comments on former offensive coordinator Jim Chaney, who accepted the same position at Pittsburgh on Sunday.

Bielema said Chaney "resigned from our staff" and wished him "nothing but the best in his future endeavors." Chaney spent two seasons on Bielema’s staff, leading an offense that averaged 20.7 points in 2013 and 31.9 points last season.

Bielema said the search for Chaney’s replacement is underway. Arkansas’ next offensive coordinator will have plenty of experience to work with. The Razorbacks return a two-year starter at quarterback (Brandon Allen), two 1,000-yard rushers (Williams and Alex Collins), their two leading receivers (Hatcher and Hunter Henry) and four starters on the offense line (Dan Skipper, Denver Kirkland, Mitch Smothers and Sebastian Tretola).

"As a head coach, I have witnessed many positive events that happen with modified transition," Bielema said in a statement. "We will find the correct fit for our returning players and coaches eager for the 2015 campaign. Once again, I am not surprised by coaches pursuing the chance to be part of something here at Arkansas that has never been done."

Bielema on Merrick

Arkansas officially introduced offensive lineman Jalen Merrick on Tuesday. Merrick announced he was committing to Arkansas on Sunday, signed a financial aid agreement with the program and will enroll in classes this month.

"We are thrilled to welcome another Florida Hog into the Razorback family," Bielema said in a statement. "We cannot wait to see how Jalen’s athleticism will improve our offensive line when he joins us this spring. Jalen comes from a great family and will be an excellent addition to our team on and off the field. We are excited to bring his contagious personality and outstanding afro to Fayetteville!"

Rivals.com and Scout.com rate Merrick, a New Smyrna Beach, Fla., native, as a four-star prospect on a five-star scale. He’s also rated as the 13th-best offensive guard in the nation, according to Rivals.com. Merrick began playing football in 2013.

Merrick chose Arkansas over Florida and Florida State.