David Weir says it will be "really difficult" for his former club Rangers to catch their bitter rivals Celtic while Brendan Rodgers remains in charge.
Since the former Liverpool manager took charge of Celtic in the summer of 2016, they have won the Scottish Premiership, the Scottish Cup and twice lifted the Scottish League Cup.
Rangers take on Celtic in the semi-finals of the Scottish Cup on Sunday, live on Sky Sports, knowing they are yet to beat their Glasgow rivals in nine attempts since Rodgers moved north of the border.
They also trail Celtic by 13 points in the league, and Weir - who represented Rangers as a player and assistant manager - believes Rodgers' presence is making life tough for his old side.
He said: "I think it will be really difficult [for Rangers to close the gap to Celtic]. He [Rodgers] is a top manager. He has a method in regards what he does. He has the respect of the players, the club, everybody and he is setting the bar high.
"Celtic's managerial appointment was really good. There was obviously a lot of thought and planning went into it. They picked the right man at the right time and he has shown their faith was right."
Yet despite Rangers' poor record against Celtic in recent seasons - and his high praise for Rodgers - Weir believes his old side can upset the odds in the cup this weekend.
Ahead of the clash at Hampden Park, Weir said: "It has been a long time not to have won an Old Firm game. So it is a massive challenge but also a good opportunity for Rangers to put a marker down.
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"I think Rangers have a chance, definitely. The past couple of Old Firm games have been tight. Celtic have managed to come out on the right end of it. Rangers have had opportunities in the game but unfortunately they haven't managed to do it."
As well as being an opportunity to record a long-awaited win against Celtic, Rangers may also view the semi-final as a chance to boost the prospects of manager Graeme Murty remaining in his post next season.
He is in charge until the end of this season, but chairman Dave King has refused to confirm whether Murty has done enough to keep his job beyond that.
Weir believes Murty has done a good job, saying: "Graeme has done really well. He has been put in a difficult situation and he has handled it well.
"Rangers are competitive, they are fighting for second place [in the Premiership] so that will be a success this season and they are in the semi-final of the cup.
"Is he right man for the job? Time will tell but winning the semi-final and finishing second in the league will certainly help that.
"I am sure he won't be thinking about his long-term future but for Rangers it is important to win the semi-final. It has been a long time since Rangers have beat Celtic.
"So that must be a great motivation, whether it is for Graeme's future or anyone's future."