Thomas Vermaelen said Chelsea's Eden Hazard is "world-class" and that he shares similarities with Lionel Messi, but suggested his Barcelona teammate is on another level to the Belgian.
Chelsea will look to Hazard to inspire them when they host Barca in the first leg of the Champions League round of 16 on Tuesday, while the Catalans will hope Messi can end a run of eight games without a goal against the Premier League champions.
Vermaelen, the Barca defender, plays with both Hazard and Messi -- one with his country and the other with his club -- and appreciates that they are both among the best players in the world.
However, he struggled to put Hazard, who has scored 87 goals in five and a half years at Stamford Bridge, alongside Messi.
"It is difficult to compare anyone to Messi, who has done it over so many years," Vermaelen told The Guardian. "But there are similarities: They're both quite small with that low centre of gravity so they can turn and twist very quickly.
"They have that element of surprise; you don't know which way they are going to go. I saw Hazard scoring against Watford so he's in good form and I know his quality: He's world-class. Eden can be right up there with the best but to compare [anyone] to Messi is so difficult.
"It's unbelievable. If you gamble that Messi's going to go one way, then he'll go the other. You would think that he does it in games but he does it day in, day out in training. That's what amazes me."
Hazard could be facing Barca on a more regular basis from next season, with regular reports placing him on Real Madrid's radar.
Vermaelen said he doesn't talk to his international teammate about transfer speculation but the two have spoken about Tuesday's Champions League game.
Chelsea go into the encounter of the back of a 4-0 win against Hull City in the fifth round of the FA Cup on Friday -- a match that allowed coach Antonio Conte to rest a number of regulars, including Hazard.
Spain striker Alvaro Morata continued his return from a back injury as a second-half substitute, with Conte later confirming Marcos Alonso will also be fit for Barca's visit, although Tiemoue Bakayoko is out.