Mikel Arteta admitted his envy at Liverpool's greater strength in depth after Arsenal lost ground in the Premier League title race with a 2-2 draw against Aston Villa.

Hours after Liverpool struck twice in stoppage-time to beat Brentford 2-0, Arsenal surrendered a two-goal advantage at Emirates Stadium to fall six points behind the leaders who have a game-in-hand.

Gabriel Martinelli and Kai Havertz had put Arsenal on track for a vital win before two goals in eight minutes from Youri Tielemans and Ollie Watkins earned Villa a point.

While Liverpool boss Arne Slot was able to call on 85 million ($103m) striker Darwin Núñez -- who scored two stoppage-time goals -- Harvey Elliott and Curtis Jones among others to help beat Brentford, injuries left Arteta only willing to make one substitution when chasing the game as Raheem Sterling, on loan from Chelsea, played the final eight minutes.

"There are moments [in the title race], obviously," he said. "[Liverpool] managed to do that, they made the subs and the subs made the impact and managed to change the game. In our side, it was the opposite even though after conceding the two goals very close to each other, the danger was because I knew how the team was, that we could go downhill because we were physically drained.

"Suddenly the team found another gear to go again and put Aston Villa in their box and go and go again and trying to find the goal that we haven't been able to score in the end."

Arsenal are attempting to add at least one player before the transfer window closes in just over a fortnight and asked whether the gap widening in the title race put extra pressure on the club to act, Arteta replied: "When you look at the performances -- I don't know how many teams are playing at this level in the league.

"But when you look at the bench, probably you say we are very short."