The story behind 49ers RB Christian McCaffrey’s touchdown pass and catch during his landmark game against the Rams

Christian McCaffrey's second game as a member of the San Francisco 49ers was one to remember, considering he became the first NFL player since 2005 (LaDanian Tomlinson) to run, catch, and throw for a touchdown in the same game. McCaffrey's rare feat in the 49ers' 31-14 win over the Los Angeles Rams on Sunday is even more fascinating when considering how his passing and receiving touchdowns came together.

McCaffrey's passing touchdown came on a trick play in the second quarter when quarterback Jimmy Garoppolo threw McCaffrey a backwards pass, which McCaffrey turned into a long throw down the sideline to a wide open Brandon Aiyuk for a touchdown. The idea for the play was that of head coach Kyle Shanahan, who after seeing McCaffrey join his team via trade from the Carolina Panthers a week earlier first considered the idea of the running back making a pass during a coach's meeting a little less than 72 hours before the game.

"I remember Thursday night when we were doing the red zone me yelling down the room to anyone who will answer, 'Does anyone know if Christian can throw?' Then (tight ends coach) Brian Fleury e-mailed or sent through text a video of him throwing a 53 yarder a few years ago," Shanahan said. "So when I saw that I felt he could throw."

The 49ers then ran the play at practice on Friday, and Shanahan liked what he saw enough to include it in the game plan for Sunday. Any trick play can come with some risk, so Shanahan was happy to see his gamble paid off with a touchdown that got the 49ers on the board in the first half.

"I wasn't laughing, I was saying 'Thank goodness,'" Shanahan said about discovering McCaffrey's passing ability. "When you're sitting there on Thursday nights, you're trying to find things that can help you call less plays and not have to call six of them. You want to find something that hopefully just makes you call one. We knew how good of a runner he was on it, so we were really hoping he was a good thrower. Once we knew that, we were pretty excited."

Quarterbacking actually runs in McCaffrey's family, as his younger brothers Dylan and Luke have played quarterback at the high school and college level (Luke has since made a move to wide receiver at Rice University). But the brother with the NFL touchdown pass is the one who didn't play the position, even though he wanted to.

"Both my little brothers are quarterbacks, so I learned a lot from them," McCaffrey said after the win over the Rams. "I used to always want to play quarterback just because it was the best position. But I've been a running back since I was seven."

McCaffrey said he wasn't caught off guard by his momentary shift to quarterback ("You've got to be ready for everything," McCaffrey said), and not surprisingly he didn't give himself much credit for the play. He instead deflected praise to Aiyuk, who made the catch to haul in his fourth touchdown reception of the season.

"BA made a great play," McCaffrey said. "That's a tough catch having to turn like that, so I was super happy when he caught it because that is a tough catch and he made me look good, so I was fired up for it."

While McCaffrey's passing touchdown came with some background, his receiving touchdown was completely a spur of the moment event. The catch came with the 49ers down 14-10 late in the third quarter on a third down play where Garoppolo considered all his options before finally settling on McCaffrey. Garoppolo can be seen scanning the field on the play before rolling right and finally finding McCaffrey, who was waiting near the sideline at first before making his way towards the end zone, where he wound up making a highlight catch.

The catch gave the 49ers their first lead of the game, which they followed with a dominant fourth quarter and a decisive win. And unlike the passing touchdown, there was no rehearsal behind any of it.

"Just a little bit of backyard football," McCaffrey said. "The play wasn't designed to go to me, but one thing I learned about Jimmy is he's a football player through and through. He showed that all week in practice. We didn't rep that, but that's just a guy going out there playing ball. Sometimes that's the best way to go about it."

Garoppolo said after the win that McCaffrey was his number five option on the play after reading the entire field from left to right. McCaffrey wasn't in his read at first, but Garoppolo came back to him and found him open for the touchdown.

"That's just being a football player," Garoppolo said. "We've been trying to emphasize that on offense -- being a football player, being in the moment, and I thought guys did a good job of that today."

McCaffrey finished the game with 18 carries for 94 yards to go with eight catches for 55 yards. His performance was even more impressive when considering he's still in the early stages of learning the 49ers' playbook and how he fits together with other players on offense after being traded from the Carolina Panthers on October 20.

"I think each week presents new challenges depending on the game plan, depending on who you're playing," McCaffrey said. "I think for me just getting comfortable with spacing and timing with the O-Line. Those guys did such an amazing job. And I think there's still a lot of meat on the bone that I left out there. So I think really understanding what we're trying to accomplish as an offense. Kyle's run game and pass game is so specific. For me, it's just about really understanding what we're trying to do with the play and helping set up blocks and finishing plays down the field and eliminating negative runs."

With a bye week on the horizon, McCaffrey will now have some spare time to become even more acclimated with his new offense ("I'll take a little time off, but I'll try to get with my coaches every day, do something every day just to continue to master the book," McCaffrey said). There should be plenty of interest in seeing what he does for an encore when the 49ers return to the field against the Los Angeles Chargers on November 13, but for now he's just happy to be on the right side of a 49ers win -- and happy to be a part of a team that is thrilled to have him aboard.

"Obviously (records) are really cool," McCaffrey said. "I think the biggest thing is coming out with a win and playing the second half like that too. I think the thing I'm most happy about is just this whole team welcoming me with open arms, especially the running back room -- guys like Jeff Wilson and Juice (Kyle Juszczyk), they just helped me all week learn everything. That just means a lot to me. Obviously those things are cool, but I'm just proud to be 49er and it felt good to get a win today."