Midfielder Gardner, who joined Forest on loan from Premier League side Aston Villa in the January transfer window, started the Championship game at the City Ground and played for the entire 90 minutes.
Former Manchester United striker Macheda, who switched to the Reds on loan from Championship rivals Cardiff City last month, also started the match, and he played for 64 minutes.
Neither Gardner nor the former Italy Under-21 international striker had a great game, as Forest suffered an embarrassing 3-0 defeat to Brentford.
After a goalless first half at the City Ground, Lasse Vibe put the Bees in the lead on 49 minutes when he pounced on a mix-up between Kelvin Wilson and keeper Dorus De Vries.
Nico Yennaris smashed home from Jake Bidwell's corner on 65 minutes before Sergi Canos swept in a fine first-time shot late on.
Forest ended the game with 10 men due to the dismissal of Eric Lichaj for two bookable offences.
Forest fans have taken to Twitter to have their say on the performances of Gardner and Macheda.
Below are some of the best comments:
Nottingham Forest fans on Gary Gardner:
Players on holiday today— Paddy Reston (@PaddyReston) April 2, 2016
Devries lichaj mills mancienne jokic gardner cohen osborn mendes vaughan macheda#nffc
Don't worry about it guys. Flavour of the month Gardner will give us a "on to Tuesday " tweet and it'll be ok #nffc— Pat O'Hara (@PatoharaPat) April 2, 2016
#nffc how on earth did Cohen get man of the match. Him and Gardner have done nothing all game— Peter Nicholson (@red_nic) April 2, 2016
Nottingham Forest fans on Federico Macheda:
#nffc players lack leadership & direction, clearly no plan. Wilson & Macheda worse championship players Iv ever seen, fans giving up.— ᎶᎪᏃ △⃒⃘ (@NffcgazTaylor) April 3, 2016
Macheda is absolutely garbage. He is so unfit a Brentford player crawling on hands & knees was quicker than him to put in a tackle #NFFC— Ben Belfield (@Benando_Torres) April 2, 2016
I truly hope we don't waste money on Mendes or Macheda. Both awful today, couldn't care less. #NFFC— Dan (@UnreliableDan) April 2, 2016