Manager Michael Beale confirmed striker Danilo suffered a fractured cheekbone while scoring Rangers' opener in a much-needed Scottish Premiership win at St Johnstone.
The Brazilian forward kickstarted a crucial victory for his under-pressure manager on his return to the XI, but his brave header came at a cost as he had to be immediately substituted along with home captain Liam Gordon after a nasty collision.
Rangers, who had a close-range Kemar Roofe finish ruled out for a narrow offside call on Abdallah Sima, again lacked clinical edge at times, which allowed the improved hosts to push for a leveller after the break.
But Steven MacLean's side, who remain winless at the bottom of the table, failed to take advantage of the second-half openings that fell their way before substitute Rabbi Matondo slotted in from a perfectly-weighted Tom Lawrence pass.
However, the "huge blow" of losing Danilo soured the positive result for Beale.
"He's had a couple of bits going on outside, so these two weeks were a chance for him to get up to speed with everything," the Rangers manager told BBC Scotland.
"He then goes and scores a really good goal, so in that moment the game is really cruel to him. I've just been told by the doctor that it's a fracture, so we'll have to see in terms of timescale when they operate on it."
On Friday, Beale did not believe his job was in immediate danger, but he conceded the obvious fact that "a football manager needs to win games of football."
Well, Saturday's trip to Perth was certainly in the "must-win" category.
Six changes, including the impressive Lawrence's first start in over a year, were made to the team which started the recent Old Firm defeat, with the re-introduction of Danilo, who took a sore one while heading in James Tavernier's cross, paying off after 16 minutes.
Had Abdallah Sima, the Brazilian's replacement, beaten Dimitar Mitov at his near post or been standing an inch further back during his role in setting up Roofe's disallowed goal, it would have been an easier afternoon for Beale and his men.
Instead, it left the door open for the Perth hosts, who saw Chris Kane - making his first start since January 2022 - almost latch on to a slack back pass from Ben Davies before completely miscuing a glorious opportunity.
But any hopes St Johnstone had of finding an equaliser were stamped out by the away side when Matondo swept in his second goal of the season with 79 minutes on the clock.
Player of the match - Tom Lawrence
Win vital for Beale, but plenty to work on - analysis
It was a day where performance was very much secondary for Beale. Failure to win may well have intensified pressure to a point of no return.
That said, the display was much more controlled from Rangers. There is still plenty to work on, though, particularly when it comes to attacking fluency.
That makes the injury to Danilo a blow. Pre-match, Beale said how his marquee summer signing was now in "the right moment physically and mentally". To back that up with a goal is a huge positive, but he is now set for a spell on the sidelines.
St Johnstone's season will not be defined by defeats to Rangers. It will be defined on being a more well-organised unit, though, which they have shown in recent games against both Old Firm clubs.
That will only make dropped points against the likes of Ross County and Dundee sting more, but with more favourable home fixtures on the horizon, the Perth side can look to rack up points.
What they said
St Johnstone manager Steven MacLean: "I thought our shape was very good. We worked ever so hard. I'm really disappointed with the two goals we conceded, one is from our corner, the other is from when we're in possession of the ball.
"I thought the players gave everything we asked of them and I thought we were a little bit unfortunate with opportunities we had. In games like these you need to take your opportunities when they come along."
Rangers manager Michael Beale: "I thought we started the game really well, good energy and we got control of the game. We scored a fantastic goal, really good combination play between James [Tavernier] and Sam [Lammers] and it's an excellent finish from Danilo.
"We didn't start the second half very well, but after that I thought we created numerous chances. We were ever so unlucky with the tight offside call, but obviously we go and score an excellent goal with Rabbi [Matondo] so hopefully that will give him a lot of confidence."
Rangers kick off their Europa League group campaign at home to Real Betis on Thursday (20:00) before hosting Motherwell next Sunday (15:00). St Johnstone travel to Leith to face Hibernian the day prior (15:00).