<text>  Southampton fear they will miss out on a permanent move for on loan defender Toby Alderweireld with parent club Atletico Madrid intent on sparking a bidding war for the player. The Belgium international has impressed for the Saints this season prior to sustaining a hamstring injury at Manchester United in January. His performances have been central to Southamptons attempt to finish in the Premier Leagues top four, and manager Ronald Koeman wants to make the loan move permanent ahead of the next campaign. However, Alderweirelds form has not gone unnoticed elsewhere. Tottenham boss Mauricio Pochettino is understood to be an admirer of the 26-year-old, while Manchester City remain in the hunt for defensive reinforcements with Manuel Pellegrini yet to find the perfect partner for captain Vincent Kompany. Southampton will face a challenge if they want to sign on loan defender Toby Alderweireld left permanently . Tottenham manager Mauricio Pochettino centre is understood to be an admirer of the defender . Manchester City boss Manuel Pellegrini centre is keen to add defensive reinforcements to his squad . Pellegrini feels that Alderweireld could act as the perfect partner to captain Vincent Kompany . Both Martin Demichelis and Eliaquim Mangala have been given opportunities but have so far not done enough to convince anybody at the Etihad Stadium that they can help take City to the next level, particularly in Europe. Southampton have a 6.8million option on Alderweireld as part of their loan deal but its thought Atletico may well use a clause in the deal that stipulates they can essentially pay 1.5m to cancel that and then sell the player to the highest bidder. Alderweireld gets across to tackle Chelseas Branislav Ivanovic left during the Premier League game . Alderweireld suffered a hamstring injury during Southamptons 1-0 victory over Manchester United . That would leave Koeman sweating on his attempts to take the former Ajax defender on a full-time basis. Southampton work to a tight budget and know theyd be facing an uphill struggle in striking a deal with Atletico this summer if bigger clubs enter the race. Alderweireld signed for Atletico from Ajax for a fee of 6.2 million in 2013, and the Spanish club are keen to recoup as much of that fee as possible. Alderweireld has 43 caps for Belgium since making his international debut back in 2009 . The 26-year-old slides in with a challenge on Newcastle Uniteds striker Emanuel Riviere left 