We need to write an original article for keyword: Diogo Costa At Chelsea. Use context provided (some bits about deadly, Diogo Costa Chelsea, Twitter link etc). Must be 600-900 words, natural headings, avoid unsupported claims, do not mention AI-generated. Use only safe HTML tags: h2, h3, p, ul, ol, li, strong, em. No other tags like div, span, etc. No markdown fences. So we need to output HTML only. We need to incorporate the keyword "Diogo Costa At Chelsea". Provide factual info. However, Diogo Costa is a Portuguese goalkeeper (Porto) not at Chelsea. There's no factual info of him at Chelsea. Must avoid unsupported claims. So we must be careful: we can discuss rumors, speculation, but must not claim something that is not verified. Use language like "reports suggest", "according to sources", but we must not assert false facts. Could say there is no official signing, etc. The context includes some unrelated bits about a Spanish striker (maybe referencing Fernando Torres?). The context: "The big Spanish striker notched 58 goals and made 120 appearances for the Blues over a three-and-a-half year spell at Stamford ..." That is about Fernando Torres. Also "Welcome to the official home of" maybe referencing Chelsea's site. Also Twitter link for CFCVideos. We need to write an article about Diogo Costa at Chelsea: maybe discuss transfer rumors, his profile, why Chelsea might be interested, his stats at Porto, etc. Must be factual: we can state his actual stats at Porto (appearances, clean sheets, etc). Must avoid claiming he is at Chelsea if not true. So we can discuss potential interest, but not claim it happened. We need 600-900 words. Let's aim ~700 words. We must only use h2, h3, p, ul, ol, li, strong, em. So headings: h2 for main sections, h3 for subsections. We must not use any other HTML tags like header, section, article, etc. Also no style attributes. Just plain tags. We must not include markdown fences. So output just HTML. Let's craft:

Diogo Costa and Chelsea: Transfer Speculation Explained

...

Then subheadings:

Goalkeeper Profile

,

Chelsea’s Goalkeeping Situation

,

What the Rumors Say

,

Social Media Reaction

,

Conclusion

. Within p tags we can include strong for emphasis, em for italic. We need to embed the Twitter link maybe as plain text? We can't use a tag for link? The allowed tags do not include a. So we cannot include hyperlink. The instruction: only safe HTML using h2, h3, p, ul, ol, li, strong, and em tags. No a tag. So we cannot embed links. So we must just mention the URLs as plain text. That's okay. We must not mention AI-generated. We must ensure word count 600-900. Let's approximate. Write about 750 words. Let's draft. We need to count words roughly. I'll write and then approximate. Draft:

Diogo Costa and Chelsea: Transfer Speculation Explained

Diogo Costa, the Portuguese international goalkeeper who has spent his professional career at FC Porto, has recently appeared in transfer discussions linking him with Chelsea. While no official move has been confirmed, the speculation has generated interest among fans and analysts. This article examines Costa’s background, Chelsea’s current goalkeeping situation, the nature of the rumors, and the reaction on social media.

Goalkeeper Profile

Born on 19 September 1999 in Barcelos, Portugal, Diogo Costa progressed through Porto’s youth academy before making his senior debut in 2020. Since then he has become the club’s first‑choice keeper, amassing over150 appearances in all competitions. His statistics include a