This is why 49ers need Vernon Davis

ST. LOUIS -- Remember, when the question going into the season was whether Colin Kaepernick and Vernon Davis could have on-field chemistry?

Now, after three weeks, it is apparent Kaepernick needs Davis on the field. The tight end missed his first game since 2007 Sunday in a loss against the Colts because of a hamstring injury. He will be a game-time decision Thursday night against the Rams.

According to ESPN Stats & Information, Kaepernick has completed just half of his pass attempts in his career with Davis off the field and 47.2 percent this season. With Davis on the field, Kaepernick has completed 62.9 percent of his throws. Davis opens up the offense. Kaepernick’s average yards per attempt with Davis is 8.9. It is a full three yards shorter without him. With Davis on the field, Kaepernick has a plus-10 touchdown-interception differential. Without him? Minus-two.

There was early concern about these two because Davis caught just six passes in the 49ers’ last six regular season games last season. But Kaepernick and Davis connected in the playoffs and in Week 1.

It's clear the 49ers’ best chance for offensive success starts with Davis being on the field.