N'Golo Kante was pictured in Chelsea training on Tuesday morning ahead of their Champions League quarter-final tie against FC Porto.
Kante missed the weekend's 5-2 defeat against West Brom due to a hamstring injury picked up on international duty with France.
But he reported for training on Tuesday morning as they geared up for their last-eight European tie on Wednesday against Porto.
The 30-year-old was a doubt for the Champions League tie, Tuchel confirmed on Friday, after saying, "It's very likely it's too soon [the first leg against Porto].
"He is doing individual training and from then on you can do the maths. Tomorrow he will miss the game and can't be in the squad. Then we arrive on Sunday, Monday and Tuesday to prepare for the game, so that leaves us with only three days.
"He has a little muscle injury, as was communicated from the national team. So my realistic approach is to think after Porto and to think about the second game against Porto."
Whether Kante will be involved or not on Wednesday remains unclear, but it is a boost for the Blues that he has returned to train with the rest of the group following his individual sessions.
Christian Pulisic was also involved on Tuesday morning at Cobham after he tweaked his hamstring during the West Brom defeat on Saturday.
Tuchel is expected to confirm the full Chelsea team news in his pre-match press conference on Tuesday afternoon to the media at Cobham over Zoom.