Former Arsenal striker Alan Smith says the squad's forwards must step up after the departure of Pierre-Emerick Aubameyang.
Aubameyang had his £350,000-a-week contract terminated earlier this week and joined Barcelona on a free transfer following a fall-out with manager Mikel Arteta.
"It should be a chance for Eddie Nketiah. You would imagine he will get more opportunities now than he did previously," Smith told Sky Sports.
"We will wait and see. It does not seem to me Arteta is at all convinced by him as a starter. He's done well in the Carabao Cup and has scored goals, but that's come mainly against clubs in the lower divisions.
"When he has had the chance from the start in the Premier League, he's not really convinced that he is somebody that can lead the line."
Meanwhile, Smith says Lacazette now has a "crucial role" to play up front for the Gunners.
"He has been in decent form and he has taken on the responsibility as one of the senior members of the team. He has been a really useful asset in the starting XI, despite a few glaring misses here and there.
"What's going to happen regarding his future in the summer is also up in the air. It's another conundrum for the club, but I am sure they are looking at another couple of strikers elsewhere, especially in the event that Lacazette does leave the club.
"But before that, he will be an important figure between now and the end of the season as the most recognised centre-forward in the squad."
Lastly, Smith adds that Arteta should give young Brazilian Martinelli an opportunity 'down the middle' as opposed to the wings where he has often found himself.
"It might just be Martinelli's time. So far, he has been given a chance on the left and he has taken that chance. In order to be given an opportunity to play through the middle you have got to show you are in good form, you are fully fit and you are playing with confidence.
"He has done that so this could be a good time to move him inside. There is precedence there, famously Thierry Henry started on the wing and moved into the striker position to great effect.
"Arsenal's formation and forward line can be quite fluid as well with a lot of interchanging of positions with Bukayo Saka, Emile Smith Rowe and Martin Odegaard so it's not like he will be positioned through the middle all the time.
"But it is certainly an option for Arteta and one he should not be afraid to have a look at."
