The Perth men started the season with two impressive away wins over Rosenborg and FC Minsk before eventually being knocked out of the Europa League qualifiers.
And their league form has now suffered a dip too. They registered a 1-1 draw against Partick on Saturday despite having enough chances to claim the three points for themselves.
Mackay was guilty himself of failing to bury a late chance against the Jags at McDiarmid Park but is convinced Saints will soon come up with a winning display.
He said: "We get ourselves into some great areas but we have not been taking advantage of them. We're missing the final pass or the final shot.
"It will come though. We will get someone here and give them a right doing.
"It's just our form has not been great other than in the cup game against Hamilton on Wednesday. We need to get back to winning games in the league soon.
"We had a great start to the season with the wins in Europe and a good start in the first three or four league games too, but since then we have lost two and drawn two. The worrying thing is that we have not played great in those games.
"There has been decent bits within them but not a 90 minutes. Hopefully next week against an Inverness team that are flying it will click for us."
Partick benefited from Steven Anderson's slip when Kris Doolan rounded goalkeeper Alan Mannus before rolling home a brilliant finish from a tight angle.
Anderson had to be replaced after hurting his thumb in his fall and the ghastly injury which left the digit pointing the wrong way could rule him out for some time.
The home side levelled when Stevie MacLean swept past Paul Gallacher in the visitors' goal three minutes before the break but the Jags keeper was just happy to be back playing after a year of frustration.
The former Scotland international was laid off at Dunfermline in March but was back between the sticks as he made his Thistle debut after a foot injury ruled out regular number one Scott Fox.
He said: "It's been difficult for me this last wee while sitting on the bench as I've been used to playing as a number one for the last few years.
"But in the last 12 months I've been made redundant at Dunfermline then had to go up to Ross County to get back playing so when I was offered the player/coach role at Thistle in the summer I was happy to take it.
"You have just got to come in and battle away and the gaffer picks whoever he feels will do the job.
"I have no complaints whatsoever. Scott Fox has done fantastically well this season - obviously down to my coaching - and he's done great for us.
"His misfortune is my gain and I got the chance to show the gaffer what I'm capable of. I thought I did okay. Do I expect to keep my place? I'll talk to the gaffer later."