The reason for the depressed demeanour was simple, as any personal pleasure derived from reaching that milestone was tempered by the knowledge that Dundee had inflicted another major setback to their season.
Defeat on the Dons’ previous visit to Dens Park resulted in their elimination from the Scottish Cup at the first hurdle and this draw looks like being equally terminal for hopes of a first league title since 1985.
Of course, publicly, Aberdeen’s players have refused to talk about mounting a challenge to Celtic, but that facade crumbled when Barry Robson revealed last week just how serious they were taking it behind the scenes.
Rooney stuck to the party line after Stephen McGinn’s goal 20 minutes from time levelled the Irishman’s wonderful first-half strike but you didn’t need to be a body language expert to know the goal, and the trinket it brought, was of little consolation.
“It’s nice to get another goal but it’s unfortunate we couldn’t get the three points.
“It would have been a lot nicer if we had got the win,” was the dejected striker’s response.
“Last week we came from behind against Motherwell to fight back and get three points and, in general, we haven’t thrown too many points away this season. So this one feels more like a defeat.
“Once we went 1-0 up I fancied us to go on and get another one, but it wasn’t to be. We conceded a soft goal and it’s disappointing to throw away two points.”
That’s certainly what it looked like as Aberdeen dominated the first half with Barcelona-style levels of possession, only to surrender the initiative meekly on a day when quality football was in short supply on a flinty surface.
Rooney’s goal in 36 minutes was a rare highlight as well as providing the perfect illustration of just why the Premiership’s leading goalscorer, now with 15, has been so prolific since returning from relative obscurity at Oldham Athletic.
The poacher’s instinct was evident as he realised Willie Dyer had drifted well behind Dundee’s defensive line and the finish into the top of the net was sublime after being picked out by Andrew Driver’s astute exploitative pass.
Now, with nine games left, Rooney is on course to pass Duncan Shearer’s tally of 27 goals set 22 years ago and perhaps the first Aberdeen player since Joe Harper to pass the 30 mark.
In fact, the former might well have been equalled by now had it not been for a wonderful Scott Bain save early in the second half and referee Craig Thomson denying him the chance to convert a penalty before the break.
Aberdeen were incensed that the official saw no intent when Dyer clearly blocked Niall McGinn’s shot with an outstretched arm but, by then, he had also rejected Dundee’s equally valid spot-kick claims when Jamie Langfield barged into Paul McGowan.
The goalkeeper’s luck ran out when he was beaten by McGinn’s near-post flick, but it was Ryan Jack who was left feeling the pain more acutely than any of his team-mates.
The Dons midfielder inexplicably busted a gut to keep the ball in play near his own corner flag only to tee up Alex Harris for a cross that allowed McGinn to claim his first goal for Dundee.
It was a gritty performance by a team denuded of several influential players and a result that leaves them in seventh place, just two points behind freefalling Hamilton Accies after a run of one defeat in nine matches.
Scott Bain’s form has been crucial to that and the former Aberdeen goalkeeper was a commanding presence again, as was the much more experienced Kevin Thomson.
The holding midfielder and club captain was an inspirational organiser when it came to making sure Dundee kept their shape, especially during the long spells when they were denied possession.
Now the aim is for the club to round off a promising first season back in the top flight by securing a place in the top half of the table by the time the Premiership splits in two next month.
Thomson said: “Hamilton have been terrific and the two teams who have come up have held their own but it would be a big disappointment not to make the top six.
“They never made many changes in the summer, we made 13, so it maybe took us a wee bit of time to gel but the manager has been terrific and has given the boys freedom to express themselves and go out and play and that’s paid dividends on the park.”
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