MADISON, Wis. By nature, football players are supposed to be tough. Sprain an ankle, rub some dirt on it, get back in the game. Pain is considered weakness, and weakness does not amount to winning.Given the disdain players generally show for sitting out with an injury, it's certainly not unusual for them to play through pain. But University of Wisconsin linebacker Ethan Armstrong is taking that concept to a whole new level.Last Saturday, Armstrong suffered a dislocated right kneecap during the fourth quarter against Purdue. The injury was bad enough that coaches wondered on the sideline if his season was over."When the normal person hears a dislocation of a kneecap, you're thinking he's done," Badgers linebackers coach Andy Buh said.But not only is Armstrong upright this week. He's been fully cleared to play against Minnesota in the annual battle for Paul Bunyan's Axe. Clearly, Armstrong's pain tolerance is higher than most. "It was pretty ugly," Armstrong said of the injury. "It just didn't look very pretty. It definitely hurt. It scared me a little bit. But nothing structurally really was wrong so it was good news, and it was good to get back out there. It was about me being able to play with it and manage it and be comfortable with it."Overcoming immense discomfort in an effort to see the field is not something new to Armstrong, a former walk-on from Ottawa, Ill. Last November, Armstrong was taken off the field by an ambulance during a game against Penn State. He had partially dislocated his right hip and missed Wisconsin's final two games. In fact, Armstrong had absorbed so many hits in his career that he required surgery on both hips one on Dec. 13 and the other on Jan. 13.They represented his third and fourth surgeries in the span of less than a year.Armstrong also had surgery on his right shoulder in 2011, which forced him to miss spring practice. Then during the season, he underwent surgery to repair a detached ligament in his thumb on a Monday. He returned to practice two days later and played the next game against Purdue while wearing a cast."Ethan's like scary tough," Badgers linebacker Chris Borland said. "He's just a tough guy. He plays through a lot of stuff that guys would sit out with. He practices with multiple things that I've known guys to sit out games with. He's kind of an old-school, hard-nosed-type guy."It's that type of personality that attracted Wisconsin coach Bret Bielema, a former linebacker himself, to Armstrong in the first place. Bielema said Armstrong told him on the sideline during Saturday's game that he was going to challenge right guard Kyle Costigan for "toughest player on the team." Costigan played this season two weeks after dislocating his kneecap and tearing cartilage. This season, Armstrong ranks third on the team in total tackles behind fellow linebackers Mike Taylor (72 tackles) and Borland (60 tackles). He has 43 tackles and four pass deflections."He's just incredibly resilient," Bielema said of Armstrong, a fourth-year junior who finally earned a scholarship in August. "He's a very, very gifted football player. Chris and Mike take away a lot of the limelight, but Ethan is as good an athlete as those two guys and probably just as fast."Borland noted Armstrong certainly was capable of recording more tackles. But the nature of the team's defense doesn't always allow for that to take place because tackles often are funneled to Borland and Taylor.Armstrong plays the strongside linebacker spot, also known as the "Sam" linebacker. Borland compared Armstrong's role to that of a strong safety because he also drops into pass coverage or sets the edge on an outside run play. Additionally, he'll play down on the tight end or fullback at the line of scrimmage."I think he unfairly doesn't get the attention he deserves," Borland said. "Partially it's because of his role. He's an unselfish guy and he does what the team needs him to do. Playing Sam linebacker isn't the most glorious position. Oftentimes you're just setting the edge or you're in pass coverage while Mike and I get to rack up stats. He's more than happy to do it. That's the type of guy he is."Buh said that when Armstrong does have opportunities to make tackles, he rarely misses. Armstrong tied a career high with 10 tackles on Oct. 6 against Illinois, a team that spread the ball around the field and created more chances for him.Taylor, who finished last season with 150 tackles to rank third in the country, has been impressed by what he's seen from Armstrong."He's playing at an all-Big Ten level right now," Taylor said. "His position is not easy by any means. It's a lot of running out in space, and being a linebacker sometimes, that's not really what you're used to playing out in space and tackling smaller, quicker guys. He's done a great job out there."Although Armstrong doesn't often receive the same accolades as his two linebacker teammates, he said he was just fine with his situation at Wisconsin.As long as he's on the field, he'll be happy even if he has to play through pain."This is why I came here, why I've worked so hard," Armstrong said. "I just don't want to give it up."Follow Jesse Temple on Twitter.