Given that leaders Manchester United are masters of closing out the title in the second half of the season, Lampard knows he and his team-mates must continue bringing home the points - the Blues have won four successive games- if they are to keep the Red Devils in sight.
"We do (have to win these games)," Lampard told Chelsea TV. "That's the position we put ourselves in, because we had that funny run through November and December.
"We were top and all of a sudden we are adrift but you can't look back at that. We have to be positive now.
"We need to put a long winning run together. We have started doing that in recent weeks."
Chelsea will again be without John Terry against Harry Redknapp's men as the club captain continues to struggle with his comeback from a knee injury.
The Blues are also without goalkeeper Petr Cech, who came off at half-time during Sunday's 2-1 win over Everton with an adductor injury.
Ross Turnbull has only started four league games since he signed from Middlesbrough in 2009, but Chelsea defender Gary Cahill is confident the 27-year-old is an able deputy.
He said: "Ross hasn't played many games in such a long time but he came in and looked like he had being playing regularly, so we have a top keeper to come in."