And it looks like Walker is finally on his way, with Trippier signing a new five year contract, which you would assume would mean he is going to be first choice next season.
Mauricio Pochettino alternated between a back four and wing-backs with regularity in the 2016/17 campaign and the pair, along with Danny Rose and Ben Davies on the left, have been rotated with, seemingly, minimal impact.
Spurs will need to strengthen this summer in order to muster another Premier League title bid and compete in the Champions League. However, one area where they already boast plenty of depth is full-back.
So what difference, if any, does it make to Tottenham when Walker and Rose are unavailable?
Walker and Rose
Tottenham's first-choice full-back pairing actually played together less than you might assume last season. The duo featured together 18 times in all competitions. That is only six matches more than Trippier and Davies started together, though all but five of those appearances came in cup competitions.
Together Walker and Rose helped Tottenham to victories in 55.5 per cent of the matches they both started with just 5.5 per cent of games ending in defeat.
In those 18 games, 35 goals have been scored, an average of 1.94 per game, while conceding just 12 – 0.66 per game. They are Pochettino's – and England's – first choice. And with good reason.
However, they didn't start together since January 31 due to a combination of Rose's injury and Walker's reported falling out with Pochettino. The suggestion is that the former Sheffield United man will leave this summer with Spurs keen to cash in on a player who is one of the best right-backs in the Premier League, with The Mirror claiming they won't settle for anything less than £50million.
Former Burnley defender Trippier was preferred at right-back towards the end of the season and his performances more than caught the eye.
It took until January 1 and the 4-1 trouncing of Watford at Vicarage Road for Trippier to get his chance in the Premier League. Until then the former Manchester City youngster had played exclusively in the cups.
He took his opportunity and then some. First he slid the ball into the box for Harry Kane to open the scoring against the Hornets. Then he whipped a tantalising cross into the middle for Kane to double Tottenham's lead.
Trippier has provided five assists in just six Premier League starts – the same number Walker has mustered in 31 starts. Though it is worth noting the 26-year-old has supplied goals in games against Watford (3), Hull City (2) and League One Millwall in the FA Cup.
Like the much-maligned Paul Pogba, Trippier would have more assists if those on the end of his passes and crosses were more ruthless in front of goal.
His delivery is excellent and he offers a different option to Walker who tends to go to the touchline before looking to cut back. Trippier, however, is more comfortable crossing from deeper positions.
With Trippier in the side Spurs won 75 per cent of their fixtures – up on 55.5 per cent with Walker and Rose. However, in the Premier League that figure rose to 100 per cent, a number which is enhanced by fixtures against Watford, Hull City and Burnley.
And Trippier's fine end to the 2016/17 campaign was recognised with a first England call-up for the squad for the World Cup qualifier against Scotland and the friendly against France.
The Welsh international has never been first-choice at Spurs. Yet his importance to Pochettino's side was underlined earlier this season when he signed a new four-and-a-half-year contract to remain in north London.
Last season was the most active of Davies' time at White Hart Lane, appearing 36 times in all competitions and making 18 Premier League starts – as many as Rose.
Spurs' win percentage with Davies in the side (58.3) was better than with Rose and Walker (55.5) – but only just. The former Swansea City defender scored as many goals as his rival for the left-back shirt (2) and provided the same number of assists (3) as well.
But in terms of their numbers the gap in quality is clear. Davies made fewer tackles and interceptions than the England man, though he came out on top for blocks and clearances.
Going forward it was a similar story. Rose has confidence and explosive pace when running at players. He is one of the Premier League's best attacking left-backs and the numbers back that up. He had far better offensive statistics than Davies for shots, key passes and dribbles.
Although Spurs did no worse statistically with Davies or Trippier filling in for Rose and Walker the numbers are skewed by the opponents faced in a lot of cases.
The latter have been Pochettino's preferred pairing throughout his time at White Hart Lane and in the case of Davies that is understandable. Rose possesses extra quality with and without the ball that the Welshman does not.
However, at right-back there is a case to be made that Trippier would offer an equally good replacement for Walker should he leave the club this summer.
He offers a different threat and would benefit from a run in the side as he is too good to play second fiddle to Walker.
That looks to be the conclusion Pochettino has come to as well, and with the new contract given to Trippier, perhaps the Argentine truly believes he is better off with him.