The club's £15m record signing was linked with a move away from the Riverside this summer.

But he scored a hat-trick on his first pre-season appearance as Boro beat Salford City 3-1, having been away with DR Congo at the Africa Cup of Nations.

"It's a whole different feeling," Assombalonga told BBC Radio Tees.

"Everyone's fit and enjoying training sessions, there's a lot of smiles on people's faces."

Having played in two of DR Congo's three group matches in Egypt and started his side's last-16 loss to Madagascar, Assombalonga was given extra time off.

Britt Assombalonga made his DR Congo debut in March 2018

But having now begun training, he says he has been impressed with the new regime at the Championship club, with former player Woodgate replacing Tony Pulis in June and bringing in Keane as his number two.

Former Liverpool, Tottenham, Inter Milan and LA Galaxy forward Keane, who is the Republic of Ireland's record goalscorer, has already left an impression on the 26-year-old.

"It's good working with him as you can get so much out of him," Assombalonga said.

"We're doing finishing every day and it's proper technical stuff and it's game-related finishing.

"The third goal we worked on on Thursday and it happened in a game so he's buzzing."

Middlesbrough boss Woodgate said of the forward: "Since he's been back from international duty he's been a different class.

"He'll score goals for us this season without a shadow of a doubt."