CB Acker traded; WR Simpson cut

After tumbling from starter to third-stringer, 49ers cornerback Kennth Acker was traded to the Chiefs on Saturday for a conditional draft pick.

The 49ers received a 2018 seventh-round pick, according to ESPN. Acker became expendable on a roster that includes plenty of capable cornerbacks. A 2014 sixth-round pick, Acker is one of seven cornerbacks the 49ers have drafted in the past three years. The other six remain on the roster.

“We feel like we’ve got some depth at the cornerback position and felt like it was a positive for him,” head coach Chip Kelly said.

After spending his first NFL season on injured reserve with a foot injury, Acker had three interceptions in 13 starts last year. However, he slid down the depth chart in the preseason.

He played just two special-team snaps in a 21-10 loss to Green Bay on Friday.

Acker is the third player the 49ers have dealt to Kansas City since 2013, joining quarterback Alex Smith and wide receiver A.J. Jenkins. The 49ers also traded with the Chiefs during the 2016 draft to move up and select Stanford guard Joshua Garnett with the No. 28 pick. Roster cuts: The 49ers began paring their roster by releasing wide receiver Jerome Simpson, offensive lineman Ian Silberman and seven other players. They also placed wide receiver Eric Rogers (torn ACL) on injured reserve.

The roster stands at 79 and must be at 75 by 1 p.m. Tuesday.

The decision to part with Simpson, 30, was a bit surprising considering he and Torrey Smith were the only wideouts on the roster with more than 36 career catches. However, Simpson (150 catches, 2,058 yards) had shown inconsistent hands since signing with the 49ers last year.

In addition, his off-the-field issues have contributed to him playing in just five games since 2013. Simpson has been arrested three times on marijuana-and/or alcohol-related charges since 2012 and served two three-game NFL suspensions.

Silberman, a sixth-round pick, was the first member of last year’s 10-man draft class to be released.

The 49ers also released receiver DiAndre Campbell, running back Kendall Gaskins, defensive lineman Darren Lake, kicker John Lunsford, linebacker Wynton McManis, offensive lineman Blake Muir and cornerback Cleveland Wallace. Injury report: Head coach Kelly said wide receiver Bruce Ellington (hamstring) and defensive tackle Quinton Dial (knee) had “precautionary MRIs,” but he didn’t know the results. Both were injured Friday. Running back Carlos Hyde is in the league’s concussion protocol after he also was injured Friday.