This is according to The Daily Star, who claim that Rochdale starlet Diba has been monitored by both London clubs this summer, with Arsenal's interest believed to have developed following his debut - a 2-1 pre-season victory away at AFC Fylde - last month.
The same source suggests that Chelsea are huge believers in his potential to shine at the very highest level of English football, with recently-promoted League One outfit 'Dale- who kicked off their 2014/15 campaign with a 1-0 defeat at home to Peterborough on Saturday - having accepted that they are likely to lose the talented 16-year-old soon.
Chelsea's goalkeeping conundrum
Goalkeepers have been a hot topic of conversation at Chelsea in recent months, with Jose Mourinho set for a difficult decision over just who he intends to play regularly between the sticks this season.
While Petr Cech has given a decade of loyal service at Stamford Bridge and remains one of the Premier League's top 'stoppers at the age of 32, the return of Belgian starlet Thibaut Courtois looks to have given Mourinho serious food for thought ahead of Chelsea's opening top-flight fixture against Burnley next Monday.
Courtois - who featured for his country at the World Cup this summer - enjoyed a hugely prosperous three-year loan spell with Atletico Madrid after joining Chelsea from K.R.C. Genk back in 2011, and is many fans' choice to start at Turf Moor as the club look to send out a statement as arguably the favourites for the title.
Diba would certainly not challenge either Cech or Courtois if he were to move to West London prior to the close of the transfer window, of course, although the prospect of learning from two such impressive goalkeepers should hold considerable appeal at this early stage of his fledgling career.
Ospina to battle Szczesny?
Like, Chelsea Arsenal are also set to witness a battle for the number one jersey in the coming months.
Gunners stalwart Wojciech Szczesny was given the nod for Sunday's impressive Community Shield triumph over Manchester City, yet it seems highly unlikely that new signing David Ospina will be content with a place on the substitutes bench following his £3 million switch from Nice.
Colombian international Ospina's arrival came after Lukasz Fabianksi decided to leave Arsenal following a seven-year spell with the club in favour of a move to Swansea City.