Bears general manager Ryan Poles didn’t rule out the Bears still adding a veteran edge rusher to their roster, either via trade or free agency.

“Obviously, there’s no certainty — It takes two to make sure it works out, so there’s a level of patience that comes with it,” he said Tuesday as veterans reported to training camp at Halas Hall. “There’s no guarantee. … I’m happy with the guys that are here. But obviously we’re gonna look to improve if we can. So if it works out, we’ll attack it.”

Veteran edge rushers still available in free agency include Yannick Ngakoue, Justin Houston, Melvin Ingram and former No. 1 overall pick Jadeveon Clowney. Ngakoue played for Bears defensive line coach Travis Smith as a member of the Raiders, while Houston played for both Poles’ Chiefs and head coach Matt Eberflus’ Colts in recent years.

The Bears have been open wanting to add a defensive end to go with free-agent signee DeMarcus Walker and returnees Trevis Gipson and Dominique Robinson. They need the help after finishing last in the NFL in sacks last season.