Former Manchester United full-back Rafael believes Romelu Lukaku has the potential to be an exceptional player for Jose Mourinho's side.
Rafael, who won three Premier League titles in a successful seven-year spell at Old Trafford, recalls Lukaku scoring a hat-trick for West Brom in a 5-5 draw with United in 2013 in Alex Ferguson's final game in charge of the club.
"For me, he is a good player and is at a good age, an age he can evolve, but if he keeps what he did last year and in the last two or three years, he will be an excellent signing."
Former Gunners star Robert Pires has suggested Lacazette will need time to adapt to English football but Rafael does not expect that process to take long.
"I admired and still admire his football a lot," said the Brazilian. "He is a very smart player, he knows how to score. He's fast, and that's all an attacker needs. I think he will do very well at Arsenal.
We could get used to seeing this celebration at Emirates Stadium pic.twitter.com/yUkt9OiXjo— Arsenal FC (@Arsenal) July 31, 2017
"I guess so [he'll need to adapt] and I think it will not take that long. In the early games, he could struggle a little, but it will be fast."