Now, the 2006 Heisman Trophy winner will have a chance to prove it.
In a move that could clear up the Ravens' clouded quarterback picture, Smith will likely work the first half of next Saturday's game against the Minnesota Vikings at M&T; Bank Stadium.
Smith described his first preseason start as "vital."
"It's very, very important for myself and my development for the team," he said.
The decision to start Smith is not an indication that he is winning the quarterback competition.
Harbaugh said it was predetermined that Smith would get his shot with the starters after Boller worked with the first team Thursday.
"We're looking at it as two games with balanced repetitions," Harbaugh said.
The Ravens' quarterback race still appears tight because Smith and Kyle Boller both showed their weaknesses in the preseason opener.
Boller looked sharp at times, completing 11 of 15 passes for 102 yards while playing nearly the entire first half. But as in previous seasons, Boller's performance was marred by turnovers - a fumble and an interception.
Smith didn't turn over the ball - the Patriots helped him by dropping a sure interception - but he wasn't accurate. He connected on five of 12 passes for 74 yards, missing wildly on some throws in the flat and hitting some big passes deep over the middle.
"I thought Troy was poised," Harbaugh said. "He threw some NFL balls in there. He did a nice job."
Smith might be considered the long-term answer at backup quarterback, but some league observers see him as the best fit to be the starter now.
After making two starts last season, Smith earned respect from veteran players for his poise. He also is comfortable rolling out of the pocket to escape pressure, which could be important behind a young and banged-up offensive line.
Asked whether next week's game could win or lose the job for him, Smith said, "I haven't stepped into the situation any day in practice, saying my performance will help me or not help me. I try to approach this the same way."
Most teams generally decide on their starters by the third preseason game because that's when the first team begins to take the majority of snaps. But Harbaugh said he might need a third game to determine his starter.
"In the end, we just have to go with the guy that is going to give us the best chance to win the next game," Harbaugh said.
While Boller and Smith struggled at times, no quarterback had a tougher time than rookie Joe Flacco.
The Ravens' first-round pick in April had a debut to forget, failing to complete a pass on three attempts and fumbling on his second play.
"That's how it is for a rookie quarterback in this league," Harbaugh said. "Joe has to learn very fast. He's a smart guy. He works his tail off. And it won't be long before he's not making those kind of mistakes and making a lot of great plays for us."
Flacco's last throw came on fourth-and-one from the New England 9-yard line. It seemed as if he could have his first touchdown pass, but instead his throw to the right flat was emphatically batted down by leaping linebacker Vince Redd.
"I thought I had one there," Flacco said. "I was getting ready to hit him, and then all of a sudden, a guy came up that seemed like he was 13 feet tall."
A rough first showing could be a mental setback for some rookies. But the Ravens are certain that Flacco will rebound quickly.
"Confidence is not going to be a problem for Joe," Harbaugh said. "He knows he is going to be a heck of a player in this league."
Said Flacco: "It was a lot of fun to get in there but definitely a learning experience. I got to move on and get better the next time we go out there."
*NoteThe Ravens have expressed interest in free-agent offensive tackle Fred Miller, a 12-year veteran who has played for the St. Louis Rams, Tennessee Titans and Chicago Bears.