LATROBE, Pa. — Sebastian Joseph-Day grinned from ear-to-ear as he walked off the field at Saint Vincent College. At 6-4 and 310 pounds, he’s a big man with an even bigger personality, an easy smile and healthy sense of humor. But his temperament was dramatically different between the lines on Tuesday.During the Steelers’ second day in pads, the intensity ramped up and tempers flared. Joseph-Day found himself right in the middle of it during one-on-one offensive line vs. defensive line drills. Lined up across from guard Mason McCormick, Joseph-Day exploded out of his stance — we’ll let him take it from here.“I was about to win the rush, and then (left tackle) Troy (Fautanu) didn’t get out the way,” Joseph-Day said. “Troy helped his buddy, like O-linemen do. So yeah, I got a little annoyed. He did that twice in a row. Did it yesterday, too.”“Annoyed” is an understatement. Joseph-Day got into Fautanu’s face. Players from both sides converged. Teammates got involved. Keanu Benton and DK Metcalf, in particular, started barking at each other. For a minute it looked like the first fight of training camp could be brewing.“I’m a little bit older now, a little bit wiser,” the 31-year-old defensive tackle said. “I’ve been around the block, and I know I gotta conserve my energy for something greater.”While the intense exchange was the most memorable moment from practice, from a football perspective Day has proven to be a versatile and impactful offseason addition. He’ll be a candidate to be the first defensive lineman off the bench behind Cameron Heyward, Derrick Harmon and Keeanu Benton in a variety of situations.DK Metcalf opens up about the Steelers' team bonding tripMike DeFaboMore from O-line vs. D-line one-on-onesAside from the near-fight, Heyward produced the highlight of the one-on-one period. The 37-year-old defensive tackle threw guard Brock Hoffman to the ground with one hand, a dominant and impressive win for the veteran defensive lineman who continues to play at a high level as he approaches 40 years old.Meanwhile, first-round pick Max Iheanachor enjoyed another solid day during the one-on-ones. One of his most noteworthy reps came when he stood firm against T.J. Watt’s bull rush. The right tackle also forced Nick Herbig wide, doing just enough to hold him off during the drill. Iheanachor also has been a problem for Jack Sawyer, who is solid in run defense but still developing as a pass rusher. Iheanachor has been handling Sawyer easily on virtually every rep.Monday Night Football mojoThe Steelers were in the middle of an individual period early in practice when the “Monday Night Football” theme song rang out over the practice field. That was signal. Both sides jogged to the 2-yard line for five high-leverage plays. Running back Rico Dowdle said that coach Mike McCarthy used a similar tactic in Dallas that he called the “mojo moment.”“That song comes on, we get together and get five plays with the team,” Dowdle said. “It can be at any point of the practice. Once you hear that song come on, you know it’s go time.”