1. The 49ers would try to sign Garoppolo to a long-term deal.
2. They would give him the franchise tag, which would give them a full season to evaluate him.
3. Despite trading for Garoppolo, the 49ers would go after a free-agent quarterback, Kirk Cousins, with whom Shanahan was more familiar.
4. The 49ers would consider drafting a quarterback in April. At that point, the no-win 49ers were vying for the No. 1 pick in the draft and might have their choice of college quarterbacks.
"Those are a lot of good options," Shanahan said. "And we didn't want to pigeon-hole ourselves on anything. So we let it go, see how it would play out."
The 49ers, of course, ended up with option No. 1 after being blown away by how effective Garoppolo was even with a limited knowledge of Shanahan's challenging offense. Nearly a month after he arrived in Santa Clara, he was inserted into the end of a game against Seattle and threw his first touchdown pass for San Francisco. He started the final five games, all of them wins.
Shanahan admitted he was surprised by how it all turned out.
"What I was shocked about was that Jimmy was able to play at a high enough level to do what he did," he said. "He didn't have time with us; he didn't know the offense inside and out. It wasn't like he was going into a situation where we were just balling and playing great. So I was nervous for Jimmy."
Garoppolo and his teammates arrive in Santa Clara for the start of the 49ers offseason program on April 16.
"I'm excited to get our players back in a couple of weeks, and once they get back (we'll) make sure we'll humble everyone right away," Shanahan said. "Everyone felt so good leaving because we won our last five games of the year, which was nice. But we also were a 6-10 team. So we've got a long way to go and we look forward to starting that as soon as the guys get back."