Romero, 28, has been a mainstay of the Tottenham backline for several seasons, but has been strongly linked with a move to Barcelona for some time now amid growing expectation that his exit could finally be sanctioned this summer.
Dominguez, 21, represents a very different profile: a promising, considerably cheaper option who would arrive with room to develop rather than replace the Argentine's experience outright. Italian reports suggest Dinamo Zagreb could command around €15m for the Spaniard, who came through Barcelona's own academy before making the move to Croatia.
Dominguez enjoyed a breakout campaign in the Croatian top flight last season, contributing two goals and three assists across 30 competitive matches as he established himself at senior level for the first time. That form has not gone unnoticed elsewhere in Europe, with Serie A sides also credited with interest in the defender over recent months, though Tottenham's confirmed interest now adds a Premier League club to the mix.
Spurs finished a lowly 17th in the Premier League last season, a reminder of how much rebuilding work remains across the squad, and defensive reinforcements have already been a clear priority this summer. The club has moved to secure centre-backs Jan Paul van Hecke, 26, and Marcos Senesi, 29, with both arrivals suggesting a squad being reshaped for greater experience and depth at the back, even as uncertainty persists over whether Romero's departure will ultimately go through before the transfer window closes.
Any move for Dominguez would likely be considered separate from the club's other defensive business rather than a direct swap, with Spurs said to view the Spaniard as a long-term addition regardless of Romero's eventual destination. His versatility and composure on the ball have drawn comparisons to some of the centre-backs Tottenham have targeted from smaller European leagues in recent windows, a scouting approach that has previously yielded promising results.
Whether Dominguez himself would be tempted by a move to a side that finished so close to relegation last season remains to be seen, though regular football and a pathway into a rebuilding project could prove an attractive pitch.