Liverpool manager Jurgen Klopp is interested to see how Jose Mourinho's return will pan out, while long-time rival Pep Guardiola believes he will do a good job at EPL club Tottenham.
Mourinho is back in the game following his appointment as Mauricio Pochettino's successor, ending an 11-month hiatus since his dismissal as Manchester United boss.
He will renew rivalries with both Liverpool and Manchester City and will be tasked with bringing Spurs closer to those sides during his tenure.
"Welcome back, Jose," Klopp said.
"Obviously it's nice to have him back. He was desperate, you could see the time he was not in.
"But on the other side Mauricio is not there any more and that shows you how things change so quickly nowadays.
"He did a brilliant job at Tottenham, no one doubts that, an outstanding coach.
"When I heard it first I could not believe in that moment, but a couple of moments later there was already a solution. Jose? He is highly motivated, so it will be interesting as well."
Guardiola, who duelled with the former Real Madrid boss when managing Barcelona and City, described his rival as an "incredible manager".
"I think you know him better than me," he said. "He was many years here with different clubs. Welcome back. He is an incredible manager and I'm pretty sure he'll do a good job."
Chelsea manager Frank Lampard revealed that he had exchanged messages with his former boss, congratulating him on his appointment.
Lampard was a key player for Chelsea during both of Mourinho's stints at Stamford Bridge and says the Portuguese is inheriting a quality team at Spurs.
"We had a couple of messages to congratulate him on his new role," Lampard said.
"I think history and results speak for themselves. The trophies and titles he's managed to win at the clubs he's worked at are not surprises, it's because of hard work that he's been in and he's done that consistently at the teams that he's been at. That's what we measure him and measure us as managers by."
Bournemouth manager Eddie Howe, who was briefly linked with replacing Pochettino, has no doubt Mourinho will still produce the goods.
"I was as surprised as everybody else watching from afar what happened this week, but Jose is an unbelievable manager and I think it's great for the league that he's back," Howe said.
Australian Associated Press