Ben Foden has been impressed with how Saints have handled the past couple of weeks.
Jim Mallinder's men have been without their Six Nations stars as well as a host of other first-team players.
They were missing four centres at Sale last Friday night, with Luther Burrell, George Pisi, JJ Hanrahan and Tom Stephenson not available.
Burrell, Pisi and Stephenson have been back in training of late, but the Sale game came too soon.
Nevertheless, Saints still managed to secure an impressive 32-12 Aviva Premiership win, their second in succession.
And they did it without influential lock Christian Day, who was ruled out, with James Craig stepping in to help ensure the set piece functioned superbly.
"Strengthening the squad was one of the big things for us and I think we've done that," said Foden, who has been skippering Saints in the absence of England flanker Tom Wood.
"Some of our results haven't really shown it, but we've got good strength in depth.
"Having someone like James Craig coming in and running the lineout with Christian Day out shows the quality of the guy and the lineout ran really well.
"We've got big players missing, but we've moved a few guys around and Nafi (Tuitavake) coming in at 13 has been a revelation.
"Me moving to the wing has allowed Ace (Ahsee Tuala) the freedom at full-back and it's worked well.
"We've had to change a few things and it helps having guys like Tei (Harrison) and Hilly (Paul Hill) coming back and putting in the shifts they do.
"You look at our squad and that's why we're so disappointed with how the season's gone so far because we feel we're a top-four side and we should be challenging for silverware."