The long-serving midfielder is closing in on the club's all-time goalscoring record, but is likely to leave Stamford Bridge at the end of the season when his contract expires
Lampard broke Bobby Tambling's record for goals scored in the FA Cup for the Blues in Sunday's win over Brentford and is also a handful of efforts away from the former striker's all-time record for the west London club.
The 34-year-old's future has been up in the air, with his current deal expiring in June, but Mata believes Lampard is "one of the best" to have ever played for the club.
"I understand why the fans want Frank here — the supporters love him," he told reporters.
"He is a great guy, a great captain who is a legend. For me and the team-mates it is an honour to play with him.
"For 10 years he has been scoring more than 10 every season in the Premier League. He is one of the best."
If Lampard is to leave the club at the end of the current campaign, Mata has identified Brazilian starlet Oscar as the man to fill the England international's boots.
"He is still 21, very young, and already a very, very good player," the Spain international added
“I feel really pleased to play with him. I’m glad because he is a great guy as well.”