Shattered Sydney Roosters fullback Michael Gordon says his side had ample opportunities to secure a spot in the grand final but were instead left to rue what could have been.

The Roosters went down 29-16 to the Cowboys in what was their third preliminary final loss in the past four seasons. 

A sluggish Roosters side took 35 minutes to get going, but once they did through tries either side of half-time, it looked as though they'd steamroll the Cowboys to book a place in next week's big one against Melbourne. 

However, as has been the case all year, errors at crucial times came back to haunt the Tricolours as they succumbed to a shock defeat that brings an end to a memorable campaign that saw them recover from last year's horror year to finish the regular season behind only the Storm. 

‌"I felt like we hung in there well and we started the second half well and we got back on top. We just couldn't put them away and they weren't going away. I just felt like we bombed a lot of chances," a dejected Gordon said after the game. 

"We put ourselves in a position to win it and they showed us how to play that game. They completed high and tackled well and we didn't. 

"I think they completed at 90-odd per cent tonight and we made a lot more tackles. They took their chances when they had them and we didn't."

Most people expected the Cowboys to be bundled out of the playoffs in the first week, but Paul Green's men are now 80 minutes away from their second premiership in three seasons following shock finals wins over the Sharks, Eels and Roosters. 

While everyone else counted them out, Gordon said his side was on high alert for a quality Cowboys performance. 

"We didn't take them lightly at all," he said. 

"We knew it was going to be a tough game and it was for most of it. In the end we weren't good enough and we fell away when we were probably expecting them to, but they never did."