The 25-year-old 'struggled' with his first touch during his Newcastle days, according to Solano.
But Carroll was always a 'monster of a striker,' the retired midfielder says, and will provide West Ham with a serious threat when they host the Magpies this Saturday.
"He has improved as a player since he came into the first team at Newcastle when I played there," Solano wrote in the Newcastle Evening Chronicle.
"Back then he struggled a bit with his first touch but in terms of aerial ability he has always been a monster of a striker.
"He is a massive threat and Paul Dummett and Mike Williamson know they will have their work cut out at Upton Park."
Alan Pardew's side travel to Upon Park to face West Ham at 3pm on Saturday, having won their last six games in all competitions and five in the Premier League.