The second-placed Hoops, who have won both of their opening matches (2-0 at Hibernian and 1-0 at Aberdeen), are preparing to meet the Terrors at Celtic Park tomorrow and Lennon is well aware of the dangers of Peter Houston's men who sit third with one win and two draws.
"We're pleased with the start we've made and our home form is going to be critical again this year," he told the club's official website.
"Dundee United are an excellent team, though, and have had some good results already this season.
"They've lost David Goodwillie but he's the only big player they've lost in the last year or two.
"Peter Houston always seems to find new ones over the year, though, and they seem to keep reinventing themselves, so as ever, they're going to be a threat."