|Scottish Cup semi-final: Celtic v Rangers|
|Venue: Hampden Park, Glasgow Date: Sunday 23 April Kick-off: 12:00 BST|
|Coverage: Live on BBC Radio Scotland, text coverage on BBC Sport website|
Pedro Caixinha's first involvement at Rangers was passive.
The Portuguese manager sat in the main stand at Celtic Park watching as the Ibrox side earned a 1-1 draw under the guidance of caretaker Graeme Murty.
Caixinha would have seen some cause for optimism in that performance, not least the doggedness of spirit that hauled the team back on to level terms after conceding the opening goal. The game wasn't a strict handover from the Mark Warburton reign, though, since Murty had already begun to try to rectify some of the team's shortcomings.
At times during this campaign, it has seemed as though the Old Firm rivals have been operating at different extremes. Following that 1-1 draw at Celtic Park, Brendan Rodgers' side had scored 74 league goals, almost double Rangers' tally of 38; at the other end of the pitch, Celtic had conceded only 17, while Rangers had lost 33 goals, again almost double.
A pattern had emerged under Warburton of Rangers tending to dominate opponents in terms of possession, but failing to convert chances and leaving themselves vulnerable in defence. Set-pieces were a particular weakness.
- Match preview: Celtic v Rangers
- Rodgers wants apology for Sviatchenko
- 'Semi win will not save Rangers' season'
- Pick your combined Old Firm XI
- Caixinha content to face Celtic's Brown
Caixinha's team are more defensively organised
Celtic were dominant in every aspect of that game. Rodgers, too, bases his approach on a possession game, but his team have been much more effective in attack - where Moussa Dembele and Scott Sinclair have been consistently lethal - and more resolute in defence.
Caixinha has only managed Rangers for five games, so it is too early to make judgements. Even so, developments have been clear, since the team have conceded only one goal in that time, and scored 10. The goal difference after that 1-1 draw at Celtic Park was +5. It is now +14.
Rangers have kept clean sheets in their past three games, having only managed back-to-back clean sheets once previously this season. Caixinha's team are noticeably more defensively organised - a consequence of greater work on that side of the game in training than under Warburton.
They have also sought to be more direct in the attacking third, showing more of a willingness to risk possession by playing through balls or delivering crosses into the penalty area.
Against Aberdeen at Pittodrie, Rangers had to survive spells of pressure - with a defence that included young, inexperienced players in David Bates and Myles Beerman - but coped. Bates, in particular, was sound in the air, although he can still look anxious in games.
The sole goal conceded under Caixinha came from a corner kick, against Motherwell, so old frailties have not been entirely eradicated. The improvements will come under intense scrutiny from Celtic, though.
Rodgers' side have drawn three of their past six games, conceding six goals in that spell, which stretches back to the 1-1 draw at Celtic Park. Yet the title was in sight and the players could have been forgiven for their consistency slipping somewhat. That will not affect them on Sunday.
The Scottish Cup is the last trophy in their sights, and they will consider themselves capable of reaching the kind of level of performance that delivered a 5-1 win over Rangers last September. As well as Dembele and Sinclair, Stuart Armstrong has grown in stature in this campaign, and he will be a roving menace in midfield against a likely central Rangers trio of Jon Toral, Jason Holt and Emerson Hyndman.
Sinclair will want to attack any space behind James Tavernier, while Beerman, for all that he has been assured for an 18-year-old who has just broken into the side, will need to cope with the occasion if he plays instead of Lee Wallace, who has been injured.
Sunday's semi-final at Hampden brings together a side that has thrived by playing free-flowing football at times, against a team that has recovered some of its self-esteem by becoming more organised and thorough.
Caixinha was a calm observer at Celtic Park, but this time he will be in the midst of the pressures and intensity of the game. Rodgers has already coped with those demands.
The Celtic manager has stressed all season that it is the collective rather than the individual that is paramount. That approach has allowed players to flourish, though, and three of the four leading Premiership scorers this season are Sinclair (20), Dembele (17) and Armstrong (13). Kenny Miller, with nine goals, is Rangers' top scorer in the league.
Every assessment of the two teams reveals Celtic's strength. Caixinha has begun his work, and there have been signs of improvement, but it is still a challenge of his tactical nous to find a way to quell the threat of Rodgers' side, while still being capable of attacking intent of their own.