Oakland Raiders defensive end Khalil Mack is headed to the Chicago Bears. Jason La Canfora of CBS Sports reported on Friday night that the San Francisco 49ers were among the teams "fully exploring" the possibility of trading for Mack. General manager John Lynch and head coach Kyle Shanahan confirmed that on Saturday.

"Yes, we would have been foolish not to (pursue Mack)," Lynch told reporters via a conference call. "The guy is a spectacular player, and we've always said we're going to exhaust every option to improve our team. We did. We went in aggressively but also knowing that we had to set some parameters. We did, and somebody else landed him, and we're excited about our team."

The 49ers had signed defensive end Jeremiah Attaochu this offseason with hopes that he would bolster a defense that ranked No. 26 in sacks last season. Attaochu, however, was part of the team's 53-man roster cut-down on Saturday.

"We've got 10 defensive linemen on our roster," Shanahan said on Saturday. "Not many teams keep more than 10. Usually, anywhere, it's nine or 10. We've got lots of guys who can play on the outside. We've got (Cassius) Marsh, we've got Dekoda (Watson), we've got Solomon (Thomas), we've got (Arik) Armstead, we've got Ronald Blair, we've got Jullian Taylor. Even [DeForest Bucker] is capable of playing on the outside."

Could the 49ers look to add a pass rusher in the near future?

"We'll look into anything that we feel can improve us," Shanahan said. "If there is an edge rusher out there that we think is better than one of our 10 guys, and he can come in and play for us, [as] with every single other position on our roster, that's what we'll do and that will be the answer of what we'll do until we're not here."