Now that Zlatan Ibrahimovic is back for Manchester United, Jose Mourinho has a couple of important decisions to make.
Arguably the most important is when to hand the Swede his first start since rupturing the ligaments in his knee seven months ago. Timing is imperative.
And the second is how to play Ibrahimovic and Romelu Lukaku in the same XI, given both are strikers and neither will settle for a place on the bench.
Lukaku upfront and Ibrahimovic as the No.10 is most likely, with the latter recently hinting at wanting to live up to his new shirt number by playing behind the striker.
There's also the option of playing them upfront together, but formations involving two strikers are rarely seen in the Premier League nowadays.
Ibrahimovic won't start a game for United for at least another couple of weeks, though, as he continues to regain fitness and match sharpness.
He looked good against Newcastle United on Saturday, but he's 36-years-old and 13 minutes' worth of football isn't enough to suggest he's ready for a full return.
Mourinho must be careful with the legendary striker and now a Swedish knee specialist has sent them both a warning.
Speaking to Expressen, per 101GG, Markus Walden explained that because Ibrahimovic has returned faster than normal, there's an even bigger risk of him re-injuring his knee ligaments.
"In general, the time before reset is between six and nine months. The trend is to approach nine months more than six," said Walden.
"The average time for a professional player is seven months to the first training session and eight months to the first match.
"The ligament may break again. The risk is the greatest in the first year after operating.
"At least half, maybe three out of four operated ligaments that break apart do so within one and a half years after surgery."
Walden believes players should wait seven months before their first training session after an ACL injury and eight months before playing a competitive match.
Ibrahimovic, however, returned to United training in October (six months after injury) and played his first game in November (seven months after injury).
By that logic the Swede is at least a month ahead of schedule, which is great news for United but could come back to haunt him.