This is a common criticism of Pochettino’s latest purchase, but the answer to the question is precisely because they are so similar. Depending on your perspective, Spurs either had multiple identities or lacked one altogether last year. Injuries and the Europa League forced heavy squad rotation last year. Danny Rose missed significant time at left back, Kyle Walker missed the end of the season at right back, and there was no consistent pairing at center back.
Andre Villas-Boas favored a high defensive line and attacking fullbacks. This worked well at the beginning of last season with Tottenham conceding only 5 goals in their first 10 league games. But then Danny Rose got injured, and things started to go wrong. In the absence of a back-up left back, Jan Vertonghen slid over from the center to provide width. This weakened the center of defense and lead to Vertonghen getting injured, further weakening the back line. In the second half of the season Kyle Walker suffered a pelvic injury, forcing Kyle Naughton to start at right back. Naughton’s inability to push up the field again limited width and restricted Tottenham’s attack.
This brings us back to DeAndre Yedlin. Athletic, attacking fullbacks are a key piece of the Bielsista philosophy that Pochettino is implementing at Tottenham, and the Yedlin purchase is consistent with the rest of the summer additions. Danny Rose signed a contract extension and Ben Davies joined from Swansea, ensuring two left backs capable of playing Pochettino’s system. Now the same is true on the right with Kyle Walker and DeAndre Yedlin.
Tottenham’s fullbacks will be expected to get up and down the field this season, just as Southampton’s were last year. It is a physically taxing assignment, and Pochettino knows that he cannot expect his starters to manage this every game while also competing in the Europa League or Champions League as well. Signing Yedlin, resigning Rose, and bringing in Davies ensures that, going forward, Tottenham can rotate their squad without changing their style of play.
This is further confirmed by the purchase of Michel Vorm from Swansea to replace Brad Friedel as the second keeper. First choice Hugo Lloris fits Pochettino’s style perfectly with his quick dashes off his line. Vorm’s ability to do the same should help the defense dramatically, as they struggled to adjust to Friedel’s more conservative play last year.
Pochettino is clearly adjusting his squad to fit a defined style of play. He has Champions League aspirations, and he understands that the Europa League may be the best way to qualify this year. Both of these require a deep team, and DeAndre Yedlin represents another step towards implementing a consistent identity.