It didn't work.
Kittle gashed the Broncos for 210 yards receiving on seven catches -- all in the first half. His biggest play was an 85-yard touchdown that gave the 49ers a 13-0 lead in the second quarter.
He was quiet in the second half but the damage had been done. His last catch was a 14-yarder that gave San Francisco a first down at Denver's 18 with 21 seconds left. Three plays and two Denver penalties later the 49ers ran it in from the 1 and led 20-0.
Kittle's big day and big half came at the expense of a banged-up secondary that was missing the quarterback of the unit in Chris Harris Jr. But there were also breakdowns that led to San Francisco getting all of its points in the first 30 minutes.
Head coach Vance Joseph said Monday that Kittle hurt his team with three plays.
"We had a plan to obviously stop him, but the first play was simply that he was the fourth option on the pivot route and he ran out of the tackles," Joseph said. "We missed three tackles and there was, I think, a 60-yard reception. The second one was a blown coverage. We're in quarters and it was a play-action jet sweep over-route by him -- very simple play. We dropped the coverage there. And the sail route, so he had three plays for about 160 yards.
"It wasn't a 15-catch day, it was really three plays for a ton of yards which we can't have, but it was really that we dropped coverage on the guy two out of three times."
Having Harris on the field would have helped. He normally covers the opponent's top wide receiver and without him the Broncos were forced to shuffle players around, especially in obvious passing downs.
"Obviously losing a guy like Chris, a Pro Bowl-type of corner, is going to hurt you," Joseph said. "I think it hurt us more moving (safety) Justin (Simmons) to nickel and having more moving pieces in the back end. Absolutely no excuses. It happened against Cincinnati and we played through it, so we wouldn't have a reason why, but when you lose some of your best players it does affect you. It creates moving pieces, simple as that, but we have no excuses for yesterday."
Harris won't be back for Saturday's game against Cleveland and rookie quarterback Baker Mayfield so Joseph and defensive coordinator Joe Woods will need to fix the mistakes in a short week. It will also help that cornerback Jamar Taylor, signed last Tuesday, will have more time to learn the defense.
"It'll help, obviously having two weeks of practice versus one," Joseph said. "He's a veteran player. He played (Sunday) and he was fine, but having Brock is going to be key for us this week."
SLOW STARTS: Denver has been plagued by slow starts this season, and Sunday was no different. This time it was costly and may have been at the price of a playoff spot.
The 49ers outgained the Broncos 311-65 in the first two quarters, a big reason why they led 20-0. Denver held San Francisco to 78 yards in the second half but the deficit was too big to overcome.
"It's all of us. We've got to coach better early and play better early, and in the last month, we've had chances to keep drives alive and we haven't," Joseph said. "Missing throws, drops on third down, play calling it's everything. We've scored, I think, three points in the last five first quarters. That can't happen."
INJURY UPDATE: Rookie cornerback Isaac Yiadom suffered a separated right shoulder on the last drive of the first half but was able to return. He is day-to-day, and with Harris still out the Broncos can ill-afford to have another member of the secondary inactive.
Cornerback Tramaine Brock, who sat out Sunday with bruised ribs, could return Saturday.
--CB Isaac Yiadom suffered a separated right shoulder in the loss at San Francisco but is considered day to day. Yiadom returned to the game after being hurt.
--CB Chris Harris Jr. had a scan done Monday on his broken left leg. Coach Vance Joseph said the leg is healing but still needs time to mend.
--LB Bradley Chubb's two sacks against the 49ers on Sunday gives him 12 for the season, which breaks the franchise record for a rookie. Von Miller (2011) and Rulon Jones (1980) had 11.5. Chubb needs 2.5 sacks to tie Jevon Kearse for the NFL rookie record. Kearse set the mark of 14.5 with Tennessee in 1999.
--CB Tramaine Brock sat out Sunday's loss at San Francisco with bruised ribs but head coach Vance Joseph said he is hopeful Brock can play against Cleveland.
--LB Brandon Marshall (knee) practiced last week but ended up as an inactive against San Francisco. Coach Vance Joseph said he is hopeful Marshall can return Saturday against Cleveland.