Gallagher's 41st-minute goal proved the difference as Argyle scored twice in as many minutes to take an unassailable two-goal lead over Cardiff.
Sturrock recalled Gallagher after he missed the 1-0 win at Coventry through a one-match suspension and was repaid as the home side won 2-1.
The Pilgrims boss admitted: "We are going to have to wait and see how Galls is. He took a knock there at the end and so we are going to have to wait on him.
"The thought now is on whether or not Tuesday's game at Southampton is going to come too quickly for some of them. That is what I have got to decide, and why we took Galls off at the end."
Argyle turned in their best first 45 minutes at home this season in the first half and deservedly led at the break.
Visiting keeper Tom Heaton saved from Emile Mpenza, making his first home start, and Gallagher before Argyle finally got a 39th-minute breakthrough.
Chris Barker's cross from deep on the left was headed on by target man Rory Fallon and Mpenza nipped in to deftly clip the ball over Heaton despite the close attention of marker Darren Purse, the Cardiff central defender and skipper.
Two minutes later Argyle led 2-0.
Chris 
"I thought we were excellent in the first 45 minutes," admitted Sturrock.
"We passed the ball well and the boys up front linked well - and we got our rewards with the two goals, which was good, because in the second half, credit to Cardiff they were the better side.
"We sat back again and (Michael) Chopra caused us all sorts of concern."
Cardiff debutant Wayne Routledge - on loan from Aston Villa - threaded the ball through to on-loan Sunderland striker Chopra on the edge of the box.
He timed his run to perfection before rounding keeper Heaton and slotting home, despite a sliding tackle from Barker.
Cardiff boss Dave Jones was left fuming by his side's overall display.
"That passing move was the only one that I saw us put together and we scored," he said.
"Apart from that we did not pass like I know we can. We have got a tough match on Tuesday (Reading at home) and will have to improve vastly on that display.
"Defensively we were all over the shop. We could not pass water from front to back.
"We can play 10 times, 100 times better than we did today but there's no hiding from the fact that we did not play well today."