Chelsea are reportedly monitoring Porto goalkeeper Diogo Costa as they consider making a serious move for a new long-term No.1 this summer.According to the Daily Mirror, the Blues are weighing up a move for the Portugal international, who is valued at around £51m.DOWNLOAD THE OFFICIAL CAUGHTOFFSIDE APP FOR ALL THE LATEST & BREAKING UPDATES – STRAIGHT TO YOUR PHONE! ON APPLE & GOOGLE PLAYThe 26-year-old has been linked with several major European clubs in recent years, but Chelsea’s interest is particularly interesting because their goalkeeping situation has rarely felt fully settled.Robert Sanchez has had spells as first choice, while Filip Jorgensen’s future has also come under scrutiny.FourFourTwo recently reported that Jorgensen has asked to leave Stamford Bridge after struggling for regular football. That could push Chelsea back into the market.Porto goalkeeper has impressed top clubsCosta would represent a different level of profile. He is experienced in the Champions League, already established with Portugal, and comfortable playing out from the back.Want more CaughtOffside coverage? Add us as a preferred source on Google to your favourites list for news you can trustThat matters for Chelsea because modern goalkeepers are not just shot-stoppers anymore.They are expected to start attacks, handle pressure and bring calm to the defense.Porto are in a strong position, though. Transfermarkt lists Costa as a Portugal international with a market value of around €40m, while TransferFeed notes that recent reports have pointed to a €60m release-clause figure.More Stories / Latest NewsJust in: Alonso ready to start major Chelsea rebuild with £51m-rated goalkeeperJun 18 2026, 8:21Update: Liverpool “optimistic” about signing another World Cup star alongside Victor MunozJun 18 2026, 7:31Journalist drops Enzo Fernandez bombshell as Chelsea midfielder takes major stepJun 18 2026, 7:28Chelsea would be sensible to sign CostaFor Chelsea, the question is whether spending heavily on a goalkeeper is the right use of funds. The squad still needs work in several areas, especially after another summer of movement.However, if the club believe Costa can finally provide stability for the next five or six years, the fee becomes easier to justify.Chelsea have spent big on potential in recent windows, but this would be more about certainty.This is still at the monitoring stage. But if Jorgensen leaves and Chelsea decide they need a clear No.1, Costa could quickly become one of the most important names on their shortlist.Journalist drops Enzo Fernandez bombshell as Chelsea midfielder takes major stepThe post Just in: Alonso ready to start major Chelsea rebuild with £51m-rated goalkeeper appeared first on CaughtOffside.