The KU defense dons red pants for Day 4 of spring practices on Tuesday.

Although the first things that truly caught my eye at Tuesday’s KU football practice — No. 4 of the spring season — were the red pants worn by the defense (first time I can recall seeing that in the past six years), the presence of a former KU quarterback stole the show while the Jayhawks stretched and warmed up.

Mark Williams, who engineered that solid 10-2 season in 1995 and helped KU finish ranked ninth in the final AP poll, was in attendance to watch his alma mater run through drills, albeit in an entirely new environment than anything he remembered seeing during his playing days.

Williams, 42, recently relocated back to Lawrence by transferring within his job and said he was thrilled to be back.

As far as him showing up for practice, Williams said KU had done a great job of reaching out to him during the past few years and added that he often found something from Kansas waiting for him in his mailbox.

Williams seemed thrilled to be back on the field and even looked like he could still play if given the chance.

Here’s the rest of what caught my eye at Tuesday’s practice, the first of the spring in which we were asked to leave early as had been normal in the past.

• Quick look at the updated offensive line: The first stringers on Tuesday, left to right, were Jordan Shelley-Smith, Bryan Peters, Keyon Haughton, Junior Visinia and Larry Mazyck. The second group included: Devon Williams, Joe Bloomfield, Jacob Bragg, D’Andre Banks and Jayson Rhodes. Again, don’t read too much into any of this, but it’s always worth keeping an eye on. As for guys who stood out. Shelley-Smith looks to be getting more comfortable every day and I thought Peters moved well, especially on some of the guard pulls and running plays where he had to cover some distance.

• As Beaty mentioned on Day 1, Corey Avery has been very limited this spring because of a shoulder injury and that has opened the door for some other guys to get some solid reps. Juco transfer Ke’aun Kinner lined up with the ones on Tuesday and Taylor Cox ran with the twos. Kinner has been getting first-team reps throughout the spring and it looks like his speed could help the KU offense replace Tony Pierson. At quarterback, Montell Cozart ran with the first offense (at least for the portion of practice we saw), followed by Michael Cummings. That battle, as you surely know by now, will be ongoing and will not be limited to just those two guys.

• Speaking of quarterbacks, I haven’t been able to see too much of the offense yet, but what I have seen has included a lot of movement by the quarterbacks. Both Cummings nad Cozart have been asked to keep the ball and run, roll out and throw and move the pocket. Even with that, the ball has come out quick and KU really seems to be emphasizing quick passes to easy targets and taking care of blocks down the field to get those guys positive yardage.

• As is common, Tuesday’s practice began with a heavy dose of special teams work. Even though that’s not that unusual, the way these guys work is. The whole thing is incredibly well organized and seems to have more of a game-prep, walk-through feel to it than a meaningless drill in a spring practice. Everywhere at every moment, these coaches are urging their guys to find a way to get better even in the smallest area.