Humza Yousaf has carried out a mini cabinet reshuffle after his beleaguered health secretary quit over a parliamentary investigation into how he racked up a near-£11,000 bill on his work iPad. The first minister attempted to refresh his government after enduring intense cross-party attacks at Holyrood over the resignation of Michael Matheson on Thursday. Matheson had previously refused repeated demands to stand down. Matheson, who resigned three hours before he was due to confirm the minimum unit price for alcoholic drinks in Scotland would rise by 30%, said he did not want to “become a distraction”. He is under investigation by Holyrood authorities after he admitted his sons had used his parliamentary iPad as a hotspot to watch football matches on their Christmas holiday in Morocco, running up a £10,935 data bill. Matheson’s resignation letter offered no apology or explanation for the timing of his decision but Yousaf’s official spokesperson said there was “clearly a very strong possibility” Matheson faces significant sanctions as a result of the investigation. “Obviously Michael believed [those were] compelling grounds to offer his resignation this morning,” he said. Holyrood authorities confirmed Matheson had not yet seen its draft conclusions, which were finalised by its corporate body on Wednesday. He will now be paid £12,712 in ministerial severance pay. Informed sources say the investigation, which is likely to be published in late February, has new evidence about his handling of the roaming bill. That raises the prospect Holyrood’s standards committee will recommend his suspension from parliament. Yousaf’s spokesperson appeared to confirm that was uppermost in Matheson’s resignation decision, and said the first minister and his aides had already been planning a reshuffle as a “contingency” exercise. Several hours later Yousaf appointed the highly regarded Neil Gray as the new health secretary, in his first reshuffle since taking office last March, with Màiri McAllan, another well-regarded younger minister, given Gray’s job of wellbeing economy secretary. Kaukab Stewart became the first woman of colour to be a Scottish minister, covering culture and international development. Rumours that Kate Forbes, Yousaf’s right-of-centre leadership rival, could be invited back into government proved unfounded. Matheson had initially claimed that the iPad bill was so large because he had not realised his sim card was out of date and no longer in contract, but insisted it was a legitimate parliamentary expense. Holyrood officials accepted his word, and agreed that £3,000 of that would be paid through his office expenses while the remainder would be funded by parliament. Matheson knew in February that £8,666 had been incurred on 2 January. In November he admitted that his wife had told him a week earlier that his sons had used his iPad as a hotspot to stream a match between bitter rivals Celtic and Rangers on that date. Yousaf, who spoke privately to Matheson on Thursday morning, said he accepted his resignation “with sadness” and that he had given the country “tremendous service”. The resignation comes a day after Elena Whitham, the drugs and alcohol policy minister, also stepped down after revealing she was suffering from post-traumatic stress. Matheson’s resignation dominated a rowdy first minister’s questions on Thursday after the Scottish Conservative leader, Douglas Ross, attacked Yousaf for showing weakness by failing to sack Matheson for lying last year. Yousaf said it was “quite galling” for a Tory to lecture any other party on integrity and honesty, given repeated scandals over ministerial conduct at Westminster. Jackie Baillie, Scottish Labour’s deputy leader, said: “This weak first minister can reshuffle the pack all he wants – the fact is that all the cards left are jokers. After 17 years it is clear that this tired SNP government is out of ideas and out of road.”