By Adam Hoge-

EVANSTON, Ill. (CBS) — Bill O’Brien and Jim Harbaugh showed up at Northwestern’s pro day Tuesday, but they were long gone by the time any of the Wildcats players took the field.

The head coaches of the Houston Texans and San Francisco 49ers, respectively, were at the Nicolet Football Center for one reason: to work out Eastern Illinois quarterback Jimmy Garoppolo.

Garoppolo was among a number of local prospects who worked out in the morning before Northwestern’s players took the field in the afternoon. But while those prospects were getting timed by scouts on the main field, Garoppolo went through private workouts on a side field, first with O’Brien and later with Harbaugh.

“It went real well,” Garoppolo said about his workout with Harbaugh. “We were back there slinging it around. I mean, he can still throw it pretty well for being an ex-quarterback and all. I learned a lot from him. He was teaching me little things here and there. I learned a lot. It was fun.”

With Colin Kaepernick entering the final year of his rookie contract, the 49ers might be looking to add another quarterback to the mix. Meanwhile, everyone knows the Texans, who hold the first overall pick in May’s NFL Draft, are in need of a quarterback. If Houston doesn’t use the first pick on a quarterback, Garoppolo would make a lot of sense for the Texans in the second round.

So it was no surprise to see O’Brien working out Garoppolo on Tuesday.

“He’s awesome. He’s an energetic guy,” Garoppolo said of O’Brien. “I got to work with him a little bit. He’s a quarterback guru, so I mean, he’s knows his stuff and I’m just trying to steal a little bit of his knowledge and put it in my game.”

Garoppolo is one of the rare prospects to participate — and throw — in every pre-draft event so far, looking at each step as an opportunity to improve his stock. So far it has worked.

“(I’ve improved) tremendously,” he said. “With the footwork especially and the knowledge of the game, I feel like I’ve come such a long way. Especially since the all-star games that I played.”

Right now, Garoppolo, who has been working with former NFL quarterback Ty Detmer, says he’s just trying to learn the nuances of the pro game, which will be a big step up from Eastern Illinois, an FCS school.

“I knew the college game inside and out, but the NFL game, there’s a huge step,” he said. “I’m trying to learn as much as I can as fast as I can. It’s process. I think I’m doing well with it.”

Working with Harbaugh and O’Brien on Tuesday was part of that process. Garoppolo also threw to the Northwestern players later in the day in front of scouts, but by then, the two NFL  coaches were gone.

They had already seen what they came to see.

Adam Hoge covers the Bears for and is a frequent contributor to 670 The Score. Follow him on Twitter at @AdamHoge.

Watch & Listen LIVE