General, only about 1000 points separates 4th from 8th right now, plenty of opportunities to move up. Even #3 is only 1355 points away.
It starts in Dubai. A win there would give Federer another 320 points, a semifinal, and there is no gain.
Focus then has to be on Indian Wells where he has won 4 times, with the last title in 2012, and can gain 820 points with a win.
It's certainly not an insurmountable task to get back to the top 4, but he has to play consistently and well.
He can gain points on the clay, particularly in Madrid, but does have a final in Rome to defend.
I think the sooner he does it, the better. It will take some pressure off.
Respectfully,
masterclass