Great Britain's medal hopes came to nought on a bruising third day of the UCI Track Cycling World Championships in Pruszkow.

It started with Laura Kenny withdrawing from the women's omnium through illness and ended with a bleeding Katie Archibald finishing seventh in her place, while her brother John failed to produce anywhere near his best to finish seventh in the men's individual pursuit.

Katie Archibald might be a former world champion in the omnium, but her lack of preparation to contest the event here showed even before a crash with American Jennifer Valente in the final points race effectively ended her challenge in Poland.

Sporting a badly swollen elbow, Archibald was distraught at the end of the day, fearing she may now miss out on Saturday's Madison and upset to have missed a chance to stake her claim in the omnium.

"I put myself in a position in the final race where I was going to have to ride differently to my normal strengths because it was just f*** up after f*** up," she said.

"Ultimately I didn't follow through on that plan. And you have to wonder how many chances you are going to get.

"I guess what's worst is I don't feel bad, I've just been so consistently ungraceful, I suppose. Unattentive, dishonest to the plan, and that's the result you get."

Archibald only found out she was racing the omnium over breakfast but said that was no excuse.

"I guess I'm concerned about the security of my place, you know," she added.

"We're usually bragging about our strength in depth but at moments like this, it means I'll be out. That's how it goes."

Kenny's withdrawal was not a huge surprise given what she said after Thursday's team pursuit.

The four-time Olympic champion had helped Britain to silver behind Australia but felt she had "let down" her teammates having been unable to perform to her usual high standards.

While British brows were furrowed, Irish eyes were smiling as Mark Downey took bronze in a thrilling men's points race.

Holland's Jan-Willem Van Schip bossed the race to improve on his silver last year, but a late surge from Downey saw him take bronze ahead of Poland's Wojciech Pzczolarski, while Britain's Mark Stewart finished eighth.

"That means a lot," Downey said.

"I've had such a bumpy winter with a lot of crashes. I've finished fourth a lot of times in my career over this past year, I know what it's like to finish fourth, so third there tonight is just a good as a win after so many emotions of being so close."