RICHMOND coach Terry Wallace will demand an explanation from the AFL about the 14 seconds that "went missing" in the dying moments of the Tigers' three-point loss to St Kilda.

Wallace was questioning a passage in the final minute of the game when the Saints kicked the ball in after Kelvin Moore hit the post from a set shot. The umpires called the ball back from that kick-in, but Wallace maintained that the clock was left ticking, running down a further 14 seconds while the ball was effectively dead.

The matter was made worse by the fact that Tigers youngster Jack Riewoldt took a shot at goal from more than 50 metres out after the siren had sounded, when there could have been more time left in the game.

"As soon as you're in a losing situation, you get the run of sour grapes when this sort of thing happens, but we are playing in such a professional industry, the AFL have such stringent rules and restrictions on us … we'll try to do it as well as we possibly can but how do you lose 14 seconds in a game of football?" Wallace said after the match.

"We'd love to have that 14 seconds with Jack Riewoldt with the ball and be able to make a decision about it."

Wallace was in no doubt about the cost of such an error.

"It's worth four points," he said.

The latest episode comes after questions were raised about the timekeeping in the final moments of Geelong's one-point win over Fremantle at Subiaco last Friday week.

Wallace said he would make a formal complaint to the AFL this week, but was unsure of what could be done.

"We'll wear the fact that we lost the game, we've got no issue with that, but there's got to be a professionalism that lifts the standard that those things don't happen," the Richmond coach said.

St Kilda will be counting the physical cost of last night's close encounter, after losing captain Nick Riewoldt and pacy midfielder Xavier Clarke to injury.

Riewoldt injured his knee when he was dragged down by Richmond defender Luke McGuane early in the second quarter.

While Riewoldt took the kick from the resulting free, he left the field immediately afterwards and headed straight to the rooms, later emerging with his left knee heavily iced and playing no further part in the game.

Saints coach Ross Lyon said he thought the injury was a medial ligament strain, but would have to wait for scans during the week.

Clarke injured his hamstring in the eighth minute of the final term and spent the rest of the match on the sidelines.

While Lyon last night said he was unsure of the severity of Clarke's injury, it does not bode well for the classy forward, who has had continuous trouble with hamstring injuries in the past.