Leigh Griffiths has warned Steven Gerrard he hasn't faced a team like Celtic yet.

The 28-year-old striker said he has been impressed with Rangers' start under Gerrard but believes they are about to face their toughest test on Sunday.

Celtic and Rangers meet in the first Old Firm derby of the season at Parkhead and Griffiths says this will be the new-look Ibrox side's biggest challenge yet.

He said: "The new manager has come in and and he's got them playing well.

"But it's a different kettle of fish when they come up against us.

"He's not come up against a team like us yet.

"Hopefully we'll do our talking on the pitch on Sunday."

Griffiths netted his 100th goal for Celtic in their 3-0 win over Suduva on Thursday night.

He said he was delighted to reach the milestone and has set himself a bigger target as he continues talks over a new contract.

He said: "I'm delighted.

"It's another milestone I've hit I just want to kick on now.

"I think the last person to do it was John Hartson so I'm in good company now.

"Not a lot of players have scored 100 goals for a club like Celtic so to be in that kind of category is great.

"If I can set my new target as 150 that would be great."

Griffith's teammates Dedryck Boyata and Moussa Dembele have been linked with moves away from Celtic as the transfer window closes on Friday night.

The Scotland striker praised the duo and said he's hoping the pair prolong their stay in Glasgow.

He said: "Listen we don't know whats going to happen, we want our best players to stay but got to respect that boys have ambitions.

"Look at Dedryck, he's proved he's a top defender, and Moussa's an out and out goalscorer - a great talent.

"We all want him to stay but we have to respect his wishes if he wants to go elsewhere, hopefully window closes and he stays."