10/23/2012 03:39 EDT | Updated 12/23/2012 05:12 EST

Blue Bombers defence knows they have to step up to keep playoff hopes alive

WINNIPEG - Now that the Winnipeg Blue Bombers' offence has found new life, the defence is looking for a way to turn around what's left of their season.

"As a defence, we've got to go out there and execute and be a lot better fundamentally," cornerback Jovon Johnson said Tuesday. "We've been giving up some plays in the secondary that we wouldn't usually give up. ... We're a lot better than what we've been showing."

The Bombers will try to keep their slim playoff hopes alive Saturday when they play the Tiger-Cats in Hamilton.

Tim Burke, who was defensive co-ordinator when he was given the interim head coach title after Paul LaPolice got the hook, has had nothing but praise for the Winnipeg offence lately.

Quarterback Buck Pierce returned and running backs Chad Simpson and Will Ford shone in last Saturday's 44-32 win in Toronto. It was the highest point total of the season for the 5-11 Blue Bombers.

However, the defence — one of the best in the league last year — has become a weak link and even Burke said he's puzzled. The defence gave up four touchdowns to the Argos' passing attack.

That's a major concern as the Bombers must win both their final games and hope Edmonton loses both of their matchups in order to make the playoffs.

Johnson, the CFL's top defensive player in 2011, said the secondary has become too easy to read on man coverage.

"Teams know what we're going to do and they've been doing things game-plan wise to attack against what we do," he said after an indoor practice.

He added they've been changing their coverage this week to address those shortcomings.

But Winnipeg will also be playing without a couple of starting defensive ends this weekend as Jason Vega and Kenny Mainor are both out with injuries. The Blue Bombers have added a couple of imports to their practice roster — Rodney Fritz and Anthony DeGrate — to fill the holes.

Fortunately for the Bombers, Fritz isn't a newcomer. He played six games for the Bombers over the last two seasons and Burke said if he had an NFL-sized roster, he's the kind of player he'd keep around.

"He was with us last year and with us in training camp this year so he knows what to do," he said. "It's just a matter of refreshing his memory."

"It feels great to be back," said Fritz, who knows his plug-and-play ability is a major asset. "I think that was probably the key thing that brought me back."

He didn't seem concerned at the flak the defence has been taking lately.

"Challenge is good some times," he said. "It's supposed to bring out the best in us as competitors. Me coming back in the situation, I know the kind of teammates we have.

"They're going to be resilient, they're going to fight for everything."