United were knocked off top spot by Manchester City on January 26 and a run of just two wins in six top-flight matches means they are now 10 points behind their rivals.
Second-placed United head to the Etihad Stadium for a Manchester derby clash on March 7 but before then they have back-to-back fixtures away to London clubs, with Sunday's match against Chelsea followed by Wednesday's game with Crystal Palace.
"We've got Chelsea just behind us, we've got City away in front of us," said Solskjaer. "Of course we can't let them run further away if we have ambitions of catching them and we can't give Chelsea too much hope to catch us either."