Milwaukee’s Stephen Jackson races by Rashard Lewis on Friday night as little goes right for the Wizards, who fell to 0-3 with another blowout loss. (Morry Gash/Associated Press)

Roger Mason Jr. angrily walked from the scorers’ table to the baseline in search of his warmups. He suddenly stopped, batted his head with both hands and shouted, “This is . . . nuts!”

The Washington Wizards have had plenty of reasons to repeat the same frustrated refrain over the past three seasons — which have been filled with losses, embarrassing and disturbing moments, and annual trips to the lottery in May.

This truncated, 66-game season is only three games old, and there have already been a couple of head-scratching incidents that have signaled that more bumbling bad times are ahead. In a 102-81 loss to the Milwaukee Bucks on Friday, Mason entered a game that he was ineligible to play in, made a jumper, received a technical foul and was sent to the showers for a situation that was beyond his control.

As he sat in the locker room incensed, Mason had to watch his teammates crumble the rest of the half, rally, then collapse again in fourth quarter — and wonder if he could’ve made a difference.

“It just stinks,” said Mason, saying that he had never witnessed a situation so bizarre in his seven-year career. “I was looking forward to making a contribution to our team. But it’s not just about me. You have to move on. I’m one player.”

The problem was the result of an error that started with the league office and worked its way down to Coach Flip Saunders, who didn’t see that Mason’s name was omitted from the 15-man roster the Bucks printed from a list the NBA provided. How Mason was left off the roster was unclear since he was active — and played — in the season’s first two games.

The Wizards’ public relations staff circled every name on the list except Jan Vesely and Maurice Evans without noticing the mistake and Saunders signed off on a sheet that had only 12 active players instead of the possible 13.

“It’s my fault,” Saunders said. “The league sends us the list and what we do is circle the guys that are active and for some reason on our list, Roger wasn’t on it and I didn’t notice it. So, I take responsibility for that. I guess the only fortunate thing is, it wasn’t a situation that cost us down the stretch.”

The situation was exacerbated when Mason went to the scorers’ table and was allowed to check in for Jordan Crawford, who had just picked up his second foul with 3 minutes 27 seconds left in the first period. Saunders said before the game that he had planned to give the veteran Mason more playing time after he received just eight minutes in the first two games. “I thought he would’ve given us some help,” Saunders said.

Mason quickly hit a turnaround jumper but Rashard Lewis (14 points) was credited with the basket, which brought the Wizards within 24-18. After a timeout, Mason was set to reenter the game when referee Danny Crawford informed him that he should not have been allowed to play.

“I was pinching myself to see if it was a joke. Obviously it wasn’t,” Mason said. “Accidents happen. Just human error. A mistake. I wish it didn’t happen to me.”

Mason shook his head, shouted an expletive, then headed back to the locker room. Once Mason exited the court, the Wizards (0-3) appeared to forget how to play, as Milwaukee (2-1) outscored them 41-23 for the rest of the half, taking a 65-41 lead at the breakon a Carlos Delfino three-pointer.

They fought back in the second half, eventually getting within 78-69 when JaVale McGee caught a lob from Crawford and dunked early in the fourth quarter. But Brandon Jennings helped put the game out of reach with a flurry of baskets, including a nifty reverse layup after splitting two defenders and long jumper that extended the lead to 19 points.

“We didn’t play hard. We just didn’t close it out,” said John Wall, who had a miserable effort with a season-low six points on 1-of-9 shooting, to go with seven assists and four turnovers. “I’m very disappointed. We lost two close ones. I think we could have won these two games, against the Nets and definitely the Bucks. No way you can make the playoffs if you’re not winning the close and tough games against teams like this.”

Saunders expressed disappointment in Wall after the game, saying, “He wasn’t good.”

Wall and Nick Young, who got the start in place of Crawford, combined to score just nine points on 2-of-19 shooting. Crawford had struggled in his role as a starter, scoring just one point the Wizards’ 101-83 loss in Atlanta two nights before. But he played well in the role of sixth man, scoring a team-high 24 points with five rebounds and five assists.

“This game, I got into a groove, but we got to find a way to win. That’s the bottom line. I’m not trying to lose,” Crawford said. “It don’t matter if I have 50. It doesn’t matter. When you lose, you become the joke of the league. We 0-3. All they talk about it how you [are] losing. It’s not better when you score more.”

Following a loss that was aided by an easily correctable mistake, the Wizards provided more fodder for laughter. “It was crazy,” Lewis, a 14-year veteran, said about the situation involving Mason. “First time I had ever seen it or heard of it. I didn’t even know it was a rule.”