OXNARD, Calif. -- Dallas Cowboys defensive tackle David Irving will not be at the opening of training camp, and it is not clear when he will show up.

According to multiple sources, Irving has been excused from the start of camp in order to deal with personal issues that played a part in him missing most of the Cowboys' offseason program in the spring.

It is not related to any legal issues or problems with the NFL. But it continues a tumultuous few months for Irving, who signed a one-year tender worth $2.9 million as a restricted free agent early in the offseason.

In June, he was hit with a four-game suspension for violating the league's substance abuse policy.

He escaped punishment by the NFL under the personal conduct policy stemming from a domestic violence allegation made in April by a former girlfriend that was later recanted, according to sources. He was cleared by the Frisco, Texas, police after it investigated a complaint by the former girlfriend, but the NFL can impose discipline, either with a fine or a suspension, even if a charge is dropped.

It will be the second straight year Irving will miss the first four games of the season, having done so in 2017 for violating the league's performance-enhancing drug policy.

Irving missed most of the offseason program as he went through a custody battle over his daughter. During the mandatory minicamp in June, he worked on his conditioning off to the side.

"I feel like I'm getting it all together," Irving said before his substance abuse suspension was announced. "I knew I should have done some things differently this offseason. Moving through it, I'm feeling much better and getting a lot of stuff handled."

Per the collective bargaining agreement, when he does return, Irving will be allowed to take part in training camp practices and preseason games before the suspension kicks in prior to the Sept. 9 opener against the Carolina Panthers.