Rooney scored the only goal of an otherwise dull affair after St Mirren new boy Eric Djemba-Djemba rounded off a home debut to forget by fouling Peter Pawlett as he burst into the area.
Aberdeen were without influential midfielder Barry Robson, who picked up a thigh strain in the Scottish Cup win over Celtic, and winger Johnny Hayes, who tweaked a hamstring in training earlier in the week.
Although hopeful that both will be fit for yet another away game next Saturday against Partick, Docherty praised the men who stepped into the breach.
"I think it's very important over any campaign that you need a full squad," said Docherty.
"We've not been let down at any stage this year with the ones we've brought in. Nicky (Low) came in and I thought he really stepped it up towards the end of the game there, he forces the corner with his shot and then he's involved with the short corner that played Peter (Pawlett) in.
"Joe Shaughnessy came in and was steady again. I think we've been lucky this year in that we've got good pros and any of the ones that we've called upon to come into the squad have not let us down.
"It's well-documented that we've been away for something like five weeks on the bounce, so we're digging in deep.
"Robson and Hayes never made it from last week's performance and for a lot of teams that would have been a big loss, but we've brought in players that have stepped up to the plate and we've managed to come to a difficult venue and take three points."
The Aberdeen squad was bolstered by the capture of goalscorer Rooney from Oldham last month, and Docherty praised the striker for the impact he has made.
"He's really brought something to us, he's clinical," said Docherty.
"But I think we've got players at the top end of the pitch who are clinical, and when they've got the platform behind them of a back four and Jamie Langfield keeping clean sheets, it gives us the opportunity to win games, so we're very pleased with how he has contributed."
Aberdeen had Langfield to thank for preserving their narrow advantage in the last minutes of the match as he saved well from Gregg Wylde's low drive, remarkably St Mirren's only attempt on target during the game.
"He's done that on countless occasions this season," Docherty said of Langfield.
"If you go through a few games from this season he's made important saves at very important times, so credit to him and credit to the back four, because that platform gives us the opportunities to go on and win games.
"I can only comment on the time we've worked with him and he's been exceptional for us. He trains really hard all week and on a Saturday his concentration levels, which you need for a goalkeeper, have been great.
"We've gathered momentum again here today picking up three points at a difficult venue, and it's important that we let other teams know that are looking in there that we're continuing to win and we look like a team that has that mentality that we're not going to sit back and accept a nothing each away from home, we look to go and win all three points."
- Sports & Recreation
- Peter Pawlett
- St Mirren
- Barry Robson