DEPTH is the key to any successful football team, and Lenny Hayes says it was what caught St Kilda out in the end.

While the Saints enjoyed one of their healthiest seasons in recent years, Hayes said they were hurt by injuries to some of their less-heralded midfielders throughout the year.

“A couple of guys who were injured hurt us. (Sean) Dempster went down with his knee, Stevie Baker - we hardly had him all year, and we really missed him. He frees one of those guys up to come into the midfield by taking a small back and lets a 'BJ' (Brendon Goddard) or a 'Grammy' (Jason Gram) to move up in the midfield,” Hayes said.

“You’re always looking for guys on the list to keep improving. We’ve still got a pretty young list, and we’re hoping there’s a bit of improvement in us.”

By contrast, Hayes said the Hawthorn midfield, which smashed the Saints on Saturday night, was blessed with a deep talent pool.

“They’ve got a lot of depth through there and they were all over us tonight and played very well. They are a good outfit and it will be a good battle for them next week,” he said.

The Saints lost another of their midfielders at the end of the game – the highly-decorated Robert Harvey bowing out after 383 games.

Hayes said his loss would be felt by his teammates in the middle.

“You can’t replace a guy like that. He’s an absolute superstar and if all of us take something out of it, it’s how hard he works and how relentless he is,” he said.

“Even in this final year, he still works his arse off and is a great role model for any young player. His legacy will live a long time for St Kilda.”

Hayes said the Saints had to work on their consistency if they were to challenge the top teams in 2009.

“There weren’t many times this year where we put four really good quarters together," he said.

"I don’t think we’re miles away, but the consistency and effort are where we have to get better.”