Chelsea’s summer can go one of two ways. It will either be a resounding success like the years of Hazard and Oscar, or it will dramatically fail like the pathetic pursuit of John Stones and the eventual signing of Michael Hector. The European Championships, with Antonio Conte managing Italy before he moves to the Bridge, will provide a final opportunity for the Blues to scout out any potential signings before the investment begins.

The chance to push through transfer early will be lost this season, you’d expect, but the Euros provide a window for players to impress, or to lose their opening of a move to the big spending Blues. Chelsea need sharp reinvestment this summer and, with much of the squad out of form or ageing, it could be a nervy few months for many current squad members.

Now, here are three players that Chelsea fans must keep their eyes on at this summer’s headline event …

Radja Nainggolan – This Belgian has been consistently linked with Chelsea already this summer and would provide a midfield tenacity that the Blues lost with the sale of Ramires. Capable in either a shuttling role in a three man midfield, a more advanced position or as a deepest midfielder, Nainggolan provides midfield versatility like Arturo Vidal and Claudio Marchisio did for Conte at Juventus.

Fearless in the tackle and a tireless competitor, Nainggolan could provide a combative nature and grit to a Chelsea midfield that has looked all too flimsy for much of the past year. Not a regular goal scorer, Nainggolan would be used as more of enforcer than creator and would give Conte balance alongside the elegant – but unathletic – Cesc Fabregas.

Andrea Barzagli – Like Nainggolan, Barzagli has already been linked with the Blues. The inevitable transfer rumours from Conte to his former Juventus players are in full swing. Chiellini, Bonucci and Barzagli were absolutely integral to Conte’s Juventus dynasty and, although the eldest of the three, seems to be the most likely to make the move. However, this seems questionable considering John Terry’s recent new contract.

Although Barzagli is now 35, he was guaranteed to make Conte’s squad for this summer’s Euros and may even start. Ideally, Chelsea would import the defensive solidity of Conte’s Juventus side into their own squad this summer, but the most efficient way of doing so may involve adding a couple of players. Barzagli knows the demands of Conte and would add further experience to a shaky defence, but it would be a marked risk to bring in another over-the-hill defender with Terry and Ivanovic remaining at the club.

Whilst you’re looking out for Barzagli, keep an eye on Bonucci and Chiellini, too, who would both be far better suited to the current state of the club.

Marko Arnautovic – With the Austrian seemingly unlikely to sign a new contract with Stoke, several clubs are likely to be sniffing around for his signature.

Stoke’s leading scorer last season will likely operate from the left flank with Austria and is a member of a team that could well spring a few surprises this summer. His previously enigmatic displays were shunned this season as he proved himself to be one of the most consistent performers in the league and showed a work ethic that many believed did not exist.

Conte’s demands of an intense, physically strong team will require hard work – which Arnautovic will need to prove he can provide – but it will need players of a stature and pace, much like the Austrian. Although he is preferred on the left – where Eden Hazard currently resides – Arnautovic, with a contract running down, would be a cheaper alternative for the Blues this summer to provide much needed goals.