Just four months ago, Babatunde Aiyegbusi left his family back in Poland, made his first visit to the United States, impressed the Vikings at a workout, got a second look at Winter Park and was signed to an NFL contract.

Now comes the difficult part — proving that he belongs in the NFL.

The 6-foot-9 offensive tackle didn't play organized football until he was in college, and the organized football he played in various European leagues wasn't up to snuff with what we've got going on here across the pond.

"This is totally different from the thing I knew before," Aiyegbusi admits.

Aiyegbusi spent the spring familiarizing himself with Minnesota, the vast Vikings playbook, his curious new teammates and proper technique.

Now the pads are on, and it's time for him to show everybody what he has learned. His power in run blocking is unmistakable as he pushes around third-string defensive lineman. But he has struggled with his technique in pass protection, and catching up on the offense has proved difficult.

"It's not easy. I've got my ups and down," Aiyegbusi said. "My strongest [attribute] is being physical at the point of attack, going forward and pushing the guys up. Worst part is that there are a lot of new plays for me and still struggling with getting it all down. So I've got my ups and downs, but coaches see that I work hard and I think that I'll be good."

During the first week of training camp, Aiyegbusi has typically been one of the last players to walk off the field, and even though he looks exhausted, he still makes time to sign autographs for kids and talk to reporters. He said he has no choice but to get extra practice in if he wants to stick around.

"It's the only way you can catch up," he said. "I'm always not satisfied with my technique. There's a long way for me to go. These guys that I practice with having been playing at a high level over here for a long time."

The coaches see the effort that the 27-year-old Pole is putting in.

"Each day he's working hard to improve," offensive line coach Jeff Davidson said. "He's got a lot to learn still in the game. A lot of us do. He is, obviously, a big physical presence. He's got a lot of stuff to learn with his game first. It's technique. It's offense. It's terms. It's everything."

The problem is Aiyegbusi doesn't have much more time to convince the Vikings to give him a spot on their practice squad (making the 53-man roster looks like a longshot for Babs at this point). In a month, after five preseason games, the Vikings will have to make their final roster cuts.

Can he convince the Vikings to remain committed to this experiment? It's too soon to say, but they believe he has been worth their time so far.

"Guys with his size don't come along very often," Davidson said. "So it's certainly worth working with a guy like that to see what he can become."