The Jamaican international is expected to join on a season-long loan, hot on the heels of the signing of Sparta Prague's Ondrej Mazuch.
Hector, 25, who joined Chelsea from Reading for £5m in the summer of 2015 and has played for a plethora of teams of loan, will join Blues team-mate Ola Aina in East Yorkshire and could be in the travelling party for the Tigers' friendly with Ajax Amsterdam.
Hector played with Eintracht Frankfurt last term.
Middlesbrough have confirmed they have agreed fee, believed to be around £6.5m, to sign West Ham and former Manchester United striker Ashley Fletcher.
The striker left West Ham's training camp in Germany this morning and is heading to Boro for contract talks.
The 21-year-old has been a loan target for Premier League sides Brighton and Huddersfield Town and has also been linked with several Championship clubs including Barnsley and Leeds United.
Sheffield Wednesday boss Carlos Carvalhal insists he will not be panicking in the club's quest to land a centre-half to boost their numbers.
Speaking after the Owls' 2-1 friendly win at Doncaster Rovers, Carvalhal said: These kind of things take time. We don’t want to make mistakes.
"We have had chances to bring in centre-halves but we have not found the correct ones.
"My staff and I have seen more than 200 centre-backs but for various reasons we have not brought one in.
"We are caring about it. We are not desperate even though everybody knows we need centre-backs.”
Leeds United are reportedly eyeing a move for Burton Albion star Jackson Irvine.
The Australia international joined Burton for £330,000 from Ross County last year, having previously moved to the UK to play for Celtic in 2010.
Meanwhile, Leeds have also been linked with a move to bring former midfielder Robert Snodgrass back to Elland Road from West Ham.
According to reports, Leeds have made enquiries for the 29-year-old but will face competition from Celtic.
Huddersfield Town have opened the door to offers for unsettled striker Nahki Wells but rebuffed talk of a £10m bid from Reading.
Wells has reportedly grown frustrated over the summer following a spate of new signings and has missed a large chunk of pre-season due to a persistent ankle problem.
“There has been no bid but I admit this is not the easiest situation for Nahki,” said David Wagner.
“Of course, he is a name that is on the market. We will listen if there is serious interest in him but, at the minute, we want to make sure Nahki is back in training. That should be the case by the end of the week.”
Doncaster Rovers manager Darren Ferguson is hoping to complete the signing of trialist midfielder Isaam Ben Khemis by the end of this week.
The French-born Tunisian, 21, a former Lorient player, has impressed during his time with Rovers, with Ferguson seeking to finalise a deal in the coming days.
On Ben Khemis, who came on as a sub against the Owls on Wednesday night, said: "Isaam has come on for half an hour and again caught the eye and done really good things and we are hoping to get that done by the end of the week to give us more balance in the middle of the pitch."
Ferguson is also chasing a Premier League loan midfielder and is hoping to get two players in ahead of the home opener with Gillingham on August 5.