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 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."