Glasgow, Scotland (My Sportsbook) - As defending Scottish Premier League champions, Rangers faces a big early-season test on Sunday as the club hosts Celtic at the Ibrox Stadium.

The Hoops enter the match with a four-point lead on their Glasgow rivals, and Rangers manager Walter Smith knows how important a win would be if his team wants to retain the title.

A loss would leave Gers seven points back at this early stage, and they find themselves in this position after three successive 0-0 draws in the league.

Smith's men were then handed a 4-1 defeat at the hands of Sevilla in the Champion League midweek, but the boss feels that this is a good time for the first Old Firm match of the season.

"It's a good game for us to have - although that will depend on the result - after the European game in midweek," Smith said.

"We would rather have an Old Firm game than another one which could mean some flatness about the place because it certainly focuses the players' minds.

"The Celtic game is one that the players know the importance of for the whole club, never mind the league situation.

"It's for your supporters and it's for bragging rights - at least until the next time the two teams play each other.

"So the importance is there for all to see."

Smith had better hope his team is focused because Celtic is poised to pick up three huge points that would give them a comfortable lead in the table.

Celtic manager Tony Mowbray will be coaching in his first Old Firm match, but he is no stranger to the rivalry having suited up for Celtic during his playing career.

"I played in a few derbies and now I'm getting the chance to manage in one," said Mowbray. "We're in a good position in that we know we have a four-point advantage at the moment. That gives us some breathing space, but we'll be as positive as we can."

Hibernian is in third place after four wins in its first six games, and Hibs hosts fourth-placed Dundee United, which is just one point back.

St Johnstone and Falkirk have yet to win in league play and they will both be hitting the road in search of their first victory.

Falkirk meets up with Motherwell at Fir Park Stadium while St Johnstone is at New Douglas Park to meet Hamilton, which is only one point ahead.

Aberdeen lost its opening game of the season but is unbeaten in its last five, and the Dons will take on Kilmarnock. Hearts travels to St Mirren in the other match this weekend.